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-rw-r--r--arch/x86/boot/compressed/sev.c86
-rw-r--r--arch/x86/coco/Makefile1
-rw-r--r--arch/x86/coco/sev/Makefile15
-rw-r--r--arch/x86/coco/sev/core.c (renamed from arch/x86/kernel/sev.c)449
-rw-r--r--arch/x86/coco/sev/shared.c (renamed from arch/x86/kernel/sev-shared.c)460
-rw-r--r--arch/x86/include/asm/cpufeatures.h1
-rw-r--r--arch/x86/include/asm/irqflags.h20
-rw-r--r--arch/x86/include/asm/msr-index.h2
-rw-r--r--arch/x86/include/asm/sev-common.h18
-rw-r--r--arch/x86/include/asm/sev.h135
-rw-r--r--arch/x86/include/uapi/asm/svm.h1
-rw-r--r--arch/x86/kernel/Makefile6
-rw-r--r--arch/x86/mm/mem_encrypt_amd.c8
-rw-r--r--arch/x86/virt/svm/sev.c44
14 files changed, 1118 insertions, 128 deletions
diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index 0457a9d7e515..cd44e120fe53 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -127,7 +127,35 @@ static bool fault_in_kernel_space(unsigned long address)
#include "../../lib/insn.c"
/* Include code for early handlers */
-#include "../../kernel/sev-shared.c"
+#include "../../coco/sev/shared.c"
+
+static struct svsm_ca *svsm_get_caa(void)
+{
+ return boot_svsm_caa;
+}
+
+static u64 svsm_get_caa_pa(void)
+{
+ return boot_svsm_caa_pa;
+}
+
+static int svsm_perform_call_protocol(struct svsm_call *call)
+{
+ struct ghcb *ghcb;
+ int ret;
+
+ if (boot_ghcb)
+ ghcb = boot_ghcb;
+ else
+ ghcb = NULL;
+
+ do {
+ ret = ghcb ? svsm_perform_ghcb_protocol(ghcb, call)
+ : svsm_perform_msr_protocol(call);
+ } while (ret == -EAGAIN);
+
+ return ret;
+}
bool sev_snp_enabled(void)
{
@@ -145,8 +173,8 @@ static void __page_state_change(unsigned long paddr, enum psc_op op)
* If private -> shared then invalidate the page before requesting the
* state change in the RMP table.
*/
- if (op == SNP_PAGE_STATE_SHARED && pvalidate(paddr, RMP_PG_SIZE_4K, 0))
- sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE);
+ if (op == SNP_PAGE_STATE_SHARED)
+ pvalidate_4k_page(paddr, paddr, false);
/* Issue VMGEXIT to change the page state in RMP table. */
sev_es_wr_ghcb_msr(GHCB_MSR_PSC_REQ_GFN(paddr >> PAGE_SHIFT, op));
@@ -161,8 +189,8 @@ static void __page_state_change(unsigned long paddr, enum psc_op op)
* Now that page state is changed in the RMP table, validate it so that it is
* consistent with the RMP entry.
*/
- if (op == SNP_PAGE_STATE_PRIVATE && pvalidate(paddr, RMP_PG_SIZE_4K, 1))
- sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE);
+ if (op == SNP_PAGE_STATE_PRIVATE)
+ pvalidate_4k_page(paddr, paddr, true);
}
void snp_set_page_private(unsigned long paddr)
@@ -256,6 +284,16 @@ void sev_es_shutdown_ghcb(void)
error("SEV-ES CPU Features missing.");
/*
+ * This denotes whether to use the GHCB MSR protocol or the GHCB
+ * shared page to perform a GHCB request. Since the GHCB page is
+ * being changed to encrypted, it can't be used to perform GHCB
+ * requests. Clear the boot_ghcb variable so that the GHCB MSR
+ * protocol is used to change the GHCB page over to an encrypted
+ * page.
+ */
+ boot_ghcb = NULL;
+
+ /*
* GHCB Page must be flushed from the cache and mapped encrypted again.
* Otherwise the running kernel will see strange cache effects when
* trying to use that page.
@@ -463,6 +501,13 @@ static bool early_snp_init(struct boot_params *bp)
setup_cpuid_table(cc_info);
/*
+ * Record the SVSM Calling Area (CA) address if the guest is not
+ * running at VMPL0. The CA will be used to communicate with the
+ * SVSM and request its services.
+ */
+ svsm_setup_ca(cc_info);
+
+ /*
* Pass run-time kernel a pointer to CC info via boot_params so EFI
* config table doesn't need to be searched again during early startup
* phase.
@@ -565,22 +610,31 @@ void sev_enable(struct boot_params *bp)
* features.
*/
if (sev_status & MSR_AMD64_SEV_SNP_ENABLED) {
- if (!(get_hv_features() & GHCB_HV_FT_SNP))
+ u64 hv_features;
+ int ret;
+
+ hv_features = get_hv_features();
+ if (!(hv_features & GHCB_HV_FT_SNP))
sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
/*
- * Enforce running at VMPL0.
- *
- * RMPADJUST modifies RMP permissions of a lesser-privileged (numerically
- * higher) privilege level. Here, clear the VMPL1 permission mask of the
- * GHCB page. If the guest is not running at VMPL0, this will fail.
+ * Enforce running at VMPL0 or with an SVSM.
*
- * If the guest is running at VMPL0, it will succeed. Even if that operation
- * modifies permission bits, it is still ok to do so currently because Linux
- * SNP guests running at VMPL0 only run at VMPL0, so VMPL1 or higher
- * permission mask changes are a don't-care.
+ * Use RMPADJUST (see the rmpadjust() function for a description of
+ * what the instruction does) to update the VMPL1 permissions of a
+ * page. If the guest is running at VMPL0, this will succeed. If the
+ * guest is running at any other VMPL, this will fail. Linux SNP guests
+ * only ever run at a single VMPL level so permission mask changes of a
+ * lesser-privileged VMPL are a don't-care.
+ */
+ ret = rmpadjust((unsigned long)&boot_ghcb_page, RMP_PG_SIZE_4K, 1);
+
+ /*
+ * Running at VMPL0 is not required if an SVSM is present and the hypervisor
+ * supports the required SVSM GHCB events.
*/
- if (rmpadjust((unsigned long)&boot_ghcb_page, RMP_PG_SIZE_4K, 1))
+ if (ret &&
+ !(snp_vmpl && (hv_features & GHCB_HV_FT_SNP_MULTI_VMPL)))
sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_NOT_VMPL0);
}
diff --git a/arch/x86/coco/Makefile b/arch/x86/coco/Makefile
index c816acf78b6a..eabdc7486538 100644
--- a/arch/x86/coco/Makefile
+++ b/arch/x86/coco/Makefile
@@ -6,3 +6,4 @@ CFLAGS_core.o += -fno-stack-protector
obj-y += core.o
obj-$(CONFIG_INTEL_TDX_GUEST) += tdx/
+obj-$(CONFIG_AMD_MEM_ENCRYPT) += sev/
diff --git a/arch/x86/coco/sev/Makefile b/arch/x86/coco/sev/Makefile
new file mode 100644
index 000000000000..4e375e7305ac
--- /dev/null
+++ b/arch/x86/coco/sev/Makefile
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-y += core.o
+
+ifdef CONFIG_FUNCTION_TRACER
+CFLAGS_REMOVE_core.o = -pg
+endif
+
+KASAN_SANITIZE_core.o := n
+KMSAN_SANITIZE_core.o := n
+KCOV_INSTRUMENT_core.o := n
+
+# With some compiler versions the generated code results in boot hangs, caused
+# by several compilation units. To be safe, disable all instrumentation.
+KCSAN_SANITIZE := n
diff --git a/arch/x86/kernel/sev.c b/arch/x86/coco/sev/core.c
index 3342ed58e168..082d61d85dfc 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/coco/sev/core.c
@@ -133,16 +133,20 @@ struct ghcb_state {
struct ghcb *ghcb;
};
+/* For early boot SVSM communication */
+static struct svsm_ca boot_svsm_ca_page __aligned(PAGE_SIZE);
+
static DEFINE_PER_CPU(struct sev_es_runtime_data*, runtime_data);
static DEFINE_PER_CPU(struct sev_es_save_area *, sev_vmsa);
+static DEFINE_PER_CPU(struct svsm_ca *, svsm_caa);
+static DEFINE_PER_CPU(u64, svsm_caa_pa);
struct sev_config {
__u64 debug : 1,
/*
- * A flag used by __set_pages_state() that indicates when the
- * per-CPU GHCB has been created and registered and thus can be
- * used by the BSP instead of the early boot GHCB.
+ * Indicates when the per-CPU GHCB has been created and registered
+ * and thus can be used by the BSP instead of the early boot GHCB.
*
* For APs, the per-CPU GHCB is created before they are started
* and registered upon startup, so this flag can be used globally
@@ -150,6 +154,15 @@ struct sev_config {
*/
ghcbs_initialized : 1,
+ /*
+ * Indicates when the per-CPU SVSM CA is to be used instead of the
+ * boot SVSM CA.
+ *
+ * For APs, the per-CPU SVSM CA is created as part of the AP
+ * bringup, so this flag can be used globally for the BSP and APs.
+ */
+ use_cas : 1,
+
__reserved : 62;
};
@@ -572,8 +585,61 @@ fault:
return ES_EXCEPTION;
}
+static __always_inline void vc_forward_exception(struct es_em_ctxt *ctxt)
+{
+ long error_code = ctxt->fi.error_code;
+ int trapnr = ctxt->fi.vector;
+
+ ctxt->regs->orig_ax = ctxt->fi.error_code;
+
+ switch (trapnr) {
+ case X86_TRAP_GP:
+ exc_general_protection(ctxt->regs, error_code);
+ break;
+ case X86_TRAP_UD:
+ exc_invalid_op(ctxt->regs);
+ break;
+ case X86_TRAP_PF:
+ write_cr2(ctxt->fi.cr2);
+ exc_page_fault(ctxt->regs, error_code);
+ break;
+ case X86_TRAP_AC:
+ exc_alignment_check(ctxt->regs, error_code);
+ break;
+ default:
+ pr_emerg("Unsupported exception in #VC instruction emulation - can't continue\n");
+ BUG();
+ }
+}
+
/* Include code shared with pre-decompression boot stage */
-#include "sev-shared.c"
+#include "shared.c"
+
+static inline struct svsm_ca *svsm_get_caa(void)
+{
+ /*
+ * Use rIP-relative references when called early in the boot. If
+ * ->use_cas is set, then it is late in the boot and no need
+ * to worry about rIP-relative references.
+ */
+ if (RIP_REL_REF(sev_cfg).use_cas)
+ return this_cpu_read(svsm_caa);
+ else
+ return RIP_REL_REF(boot_svsm_caa);
+}
+
+static u64 svsm_get_caa_pa(void)
+{
+ /*
+ * Use rIP-relative references when called early in the boot. If
+ * ->use_cas is set, then it is late in the boot and no need
+ * to worry about rIP-relative references.
+ */
+ if (RIP_REL_REF(sev_cfg).use_cas)
+ return this_cpu_read(svsm_caa_pa);
+ else
+ return RIP_REL_REF(boot_svsm_caa_pa);
+}
static noinstr void __sev_put_ghcb(struct ghcb_state *state)
{
@@ -600,6 +666,44 @@ static noinstr void __sev_put_ghcb(struct ghcb_state *state)
}
}
+static int svsm_perform_call_protocol(struct svsm_call *call)
+{
+ struct ghcb_state state;
+ unsigned long flags;
+ struct ghcb *ghcb;
+ int ret;
+
+ /*
+ * This can be called very early in the boot, use native functions in
+ * order to avoid paravirt issues.
+ */
+ flags = native_local_irq_save();
+
+ /*
+ * Use rip-relative references when called early in the boot. If
+ * ghcbs_initialized is set, then it is late in the boot and no need
+ * to worry about rip-relative references in called functions.
+ */
+ if (RIP_REL_REF(sev_cfg).ghcbs_initialized)
+ ghcb = __sev_get_ghcb(&state);
+ else if (RIP_REL_REF(boot_ghcb))
+ ghcb = RIP_REL_REF(boot_ghcb);
+ else
+ ghcb = NULL;
+
+ do {
+ ret = ghcb ? svsm_perform_ghcb_protocol(ghcb, call)
+ : svsm_perform_msr_protocol(call);
+ } while (ret == -EAGAIN);
+
+ if (RIP_REL_REF(sev_cfg).ghcbs_initialized)
+ __sev_put_ghcb(&state);
+
+ native_local_irq_restore(flags);
+
+ return ret;
+}
+
void noinstr __sev_es_nmi_complete(void)
{
struct ghcb_state state;
@@ -709,7 +813,6 @@ early_set_pages_state(unsigned long vaddr, unsigned long paddr,
{
unsigned long paddr_end;
u64 val;
- int ret;
vaddr = vaddr & PAGE_MASK;
@@ -717,12 +820,9 @@ early_set_pages_state(unsigned long vaddr, unsigned long paddr,
paddr_end = paddr + (npages << PAGE_SHIFT);
while (paddr < paddr_end) {
- if (op == SNP_PAGE_STATE_SHARED) {
- /* Page validation must be rescinded before changing to shared */
- ret = pvalidate(vaddr, RMP_PG_SIZE_4K, false);
- if (WARN(ret, "Failed to validate address 0x%lx ret %d", paddr, ret))
- goto e_term;
- }
+ /* Page validation must be rescinded before changing to shared */
+ if (op == SNP_PAGE_STATE_SHARED)
+ pvalidate_4k_page(vaddr, paddr, false);
/*
* Use the MSR protocol because this function can be called before
@@ -744,12 +844,9 @@ early_set_pages_state(unsigned long vaddr, unsigned long paddr,
paddr, GHCB_MSR_PSC_RESP_VAL(val)))
goto e_term;
- if (op == SNP_PAGE_STATE_PRIVATE) {
- /* Page validation must be performed after changing to private */
- ret = pvalidate(vaddr, RMP_PG_SIZE_4K, true);
- if (WARN(ret, "Failed to validate address 0x%lx ret %d", paddr, ret))
- goto e_term;
- }
+ /* Page validation must be performed after changing to private */
+ if (op == SNP_PAGE_STATE_PRIVATE)
+ pvalidate_4k_page(vaddr, paddr, true);
vaddr += PAGE_SIZE;
paddr += PAGE_SIZE;
@@ -913,22 +1010,49 @@ void snp_accept_memory(phys_addr_t start, phys_addr_t end)
set_pages_state(vaddr, npages, SNP_PAGE_STATE_PRIVATE);
}
-static int snp_set_vmsa(void *va, bool vmsa)
+static int snp_set_vmsa(void *va, void *caa, int apic_id, bool make_vmsa)
{
- u64 attrs;
+ int ret;
- /*
- * Running at VMPL0 allows the kernel to change the VMSA bit for a page
- * using the RMPADJUST instruction. However, for the instruction to
- * succeed it must target the permissions of a lesser privileged
- * (higher numbered) VMPL level, so use VMPL1 (refer to the RMPADJUST
- * instruction in the AMD64 APM Volume 3).
- */
- attrs = 1;
- if (vmsa)
- attrs |= RMPADJUST_VMSA_PAGE_BIT;
+ if (snp_vmpl) {
+ struct svsm_call call = {};
+ unsigned long flags;
+
+ local_irq_save(flags);
- return rmpadjust((unsigned long)va, RMP_PG_SIZE_4K, attrs);
+ call.caa = this_cpu_read(svsm_caa);
+ call.rcx = __pa(va);
+
+ if (make_vmsa) {
+ /* Protocol 0, Call ID 2 */
+ call.rax = SVSM_CORE_CALL(SVSM_CORE_CREATE_VCPU);
+ call.rdx = __pa(caa);
+ call.r8 = apic_id;
+ } else {
+ /* Protocol 0, Call ID 3 */
+ call.rax = SVSM_CORE_CALL(SVSM_CORE_DELETE_VCPU);
+ }
+
+ ret = svsm_perform_call_protocol(&call);
+
+ local_irq_restore(flags);
+ } else {
+ /*
+ * If the kernel runs at VMPL0, it can change the VMSA
+ * bit for a page using the RMPADJUST instruction.
+ * However, for the instruction to succeed it must
+ * target the permissions of a lesser privileged (higher
+ * numbered) VMPL level, so use VMPL1.
+ */
+ u64 attrs = 1;
+
+ if (make_vmsa)
+ attrs |= RMPADJUST_VMSA_PAGE_BIT;
+
+ ret = rmpadjust((unsigned long)va, RMP_PG_SIZE_4K, attrs);
+ }
+
+ return ret;
}
#define __ATTR_BASE (SVM_SELECTOR_P_MASK | SVM_SELECTOR_S_MASK)
@@ -962,11 +1086,11 @@ static void *snp_alloc_vmsa_page(int cpu)
return page_address(p + 1);
}
-static void snp_cleanup_vmsa(struct sev_es_save_area *vmsa)
+static void snp_cleanup_vmsa(struct sev_es_save_area *vmsa, int apic_id)
{
int err;
- err = snp_set_vmsa(vmsa, false);
+ err = snp_set_vmsa(vmsa, NULL, apic_id, false);
if (err)
pr_err("clear VMSA page failed (%u), leaking page\n", err);
else
@@ -977,6 +1101,7 @@ static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip)
{
struct sev_es_save_area *cur_vmsa, *vmsa;
struct ghcb_state state;
+ struct svsm_ca *caa;
unsigned long flags;
struct ghcb *ghcb;
u8 sipi_vector;
@@ -1023,6 +1148,9 @@ static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip)
if (!vmsa)
return -ENOMEM;
+ /* If an SVSM is present, the SVSM per-CPU CAA will be !NULL */
+ caa = per_cpu(svsm_caa, cpu);
+
/* CR4 should maintain the MCE value */
cr4 = native_read_cr4() & X86_CR4_MCE;
@@ -1070,11 +1198,11 @@ static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip)
* VMPL level
* SEV_FEATURES (matches the SEV STATUS MSR right shifted 2 bits)
*/
- vmsa->vmpl = 0;
+ vmsa->vmpl = snp_vmpl;
vmsa->sev_features = sev_status >> 2;
/* Switch the page over to a VMSA page now that it is initialized */
- ret = snp_set_vmsa(vmsa, true);
+ ret = snp_set_vmsa(vmsa, caa, apic_id, true);
if (ret) {
pr_err("set VMSA page failed (%u)\n", ret);
free_page((unsigned long)vmsa);
@@ -1090,7 +1218,10 @@ static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip)
vc_ghcb_invalidate(ghcb);
ghcb_set_rax(ghcb, vmsa->sev_features);
ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_AP_CREATION);
- ghcb_set_sw_exit_info_1(ghcb, ((u64)apic_id << 32) | SVM_VMGEXIT_AP_CREATE);
+ ghcb_set_sw_exit_info_1(ghcb,
+ ((u64)apic_id << 32) |
+ ((u64)snp_vmpl << 16) |
+ SVM_VMGEXIT_AP_CREATE);
ghcb_set_sw_exit_info_2(ghcb, __pa(vmsa));
sev_es_wr_ghcb_msr(__pa(ghcb));
@@ -1108,13 +1239,13 @@ static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip)
/* Perform cleanup if there was an error */
if (ret) {
- snp_cleanup_vmsa(vmsa);
+ snp_cleanup_vmsa(vmsa, apic_id);
vmsa = NULL;
}
/* Free up any previous VMSA page */
if (cur_vmsa)
- snp_cleanup_vmsa(cur_vmsa);
+ snp_cleanup_vmsa(cur_vmsa, apic_id);
/* Record the current VMSA page */
per_cpu(sev_vmsa, cpu) = vmsa;
@@ -1209,6 +1340,17 @@ static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
/* Is it a WRMSR? */
exit_info_1 = (ctxt->insn.opcode.bytes[1] == 0x30) ? 1 : 0;
+ if (regs->cx == MSR_SVSM_CAA) {
+ /* Writes to the SVSM CAA msr are ignored */
+ if (exit_info_1)
+ return ES_OK;
+
+ regs->ax = lower_32_bits(this_cpu_read(svsm_caa_pa));
+ regs->dx = upper_32_bits(this_cpu_read(svsm_caa_pa));
+
+ return ES_OK;
+ }
+
ghcb_set_rcx(ghcb, regs->cx);
if (exit_info_1) {
ghcb_set_rax(ghcb, regs->ax);
@@ -1346,6 +1488,18 @@ static void __init alloc_runtime_data(int cpu)
panic("Can't allocate SEV-ES runtime data");
per_cpu(runtime_data, cpu) = data;
+
+ if (snp_vmpl) {
+ struct svsm_ca *caa;
+
+ /* Allocate the SVSM CA page if an SVSM is present */
+ caa = memblock_alloc(sizeof(*caa), PAGE_SIZE);
+ if (!caa)
+ panic("Can't allocate SVSM CA page\n");
+
+ per_cpu(svsm_caa, cpu) = caa;
+ per_cpu(svsm_caa_pa, cpu) = __pa(caa);
+ }
}
static void __init init_ghcb(int cpu)
@@ -1395,6 +1549,32 @@ void __init sev_es_init_vc_handling(void)
init_ghcb(cpu);
}
+ /* If running under an SVSM, switch to the per-cpu CA */
+ if (snp_vmpl) {
+ struct svsm_call call = {};
+ unsigned long flags;
+ int ret;
+
+ local_irq_save(flags);
+
+ /*
+ * SVSM_CORE_REMAP_CA call:
+ * RAX = 0 (Protocol=0, CallID=0)
+ * RCX = New CA GPA
+ */
+ call.caa = svsm_get_caa();
+ call.rax = SVSM_CORE_CALL(SVSM_CORE_REMAP_CA);
+ call.rcx = this_cpu_read(svsm_caa_pa);
+ ret = svsm_perform_call_protocol(&call);
+ if (ret)
+ panic("Can't remap the SVSM CA, ret=%d, rax_out=0x%llx\n",
+ ret, call.rax_out);
+
+ sev_cfg.use_cas = true;
+
+ local_irq_restore(flags);
+ }
+
sev_es_setup_play_dead();
/* Secondary CPUs use the runtime #VC handler */
@@ -1819,33 +1999,6 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
return result;
}
-static __always_inline void vc_forward_exception(struct es_em_ctxt *ctxt)
-{
- long error_code = ctxt->fi.error_code;
- int trapnr = ctxt->fi.vector;
-
- ctxt->regs->orig_ax = ctxt->fi.error_code;
-
- switch (trapnr) {
- case X86_TRAP_GP:
- exc_general_protection(ctxt->regs, error_code);
- break;
- case X86_TRAP_UD:
- exc_invalid_op(ctxt->regs);
- break;
- case X86_TRAP_PF:
- write_cr2(ctxt->fi.cr2);
- exc_page_fault(ctxt->regs, error_code);
- break;
- case X86_TRAP_AC:
- exc_alignment_check(ctxt->regs, error_code);
- break;
- default:
- pr_emerg("Unsupported exception in #VC instruction emulation - can't continue\n");
- BUG();
- }
-}
-
static __always_inline bool is_vc2_stack(unsigned long sp)
{
return (sp >= __this_cpu_ist_bottom_va(VC2) && sp < __this_cpu_ist_top_va(VC2));
@@ -2095,6 +2248,47 @@ found_cc_info:
return cc_info;
}
+static __head void svsm_setup(struct cc_blob_sev_info *cc_info)
+{
+ struct svsm_call call = {};
+ int ret;
+ u64 pa;
+
+ /*
+ * Record the SVSM Calling Area address (CAA) if the guest is not
+ * running at VMPL0. The CA will be used to communicate with the
+ * SVSM to perform the SVSM services.
+ */
+ if (!svsm_setup_ca(cc_info))
+ return;
+
+ /*
+ * It is very early in the boot and the kernel is running identity
+ * mapped but without having adjusted the pagetables to where the
+ * kernel was loaded (physbase), so the get the CA address using
+ * RIP-relative addressing.
+ */
+ pa = (u64)&RIP_REL_REF(boot_svsm_ca_page);
+
+ /*
+ * Switch over to the boot SVSM CA while the current CA is still
+ * addressable. There is no GHCB at this point so use the MSR protocol.
+ *
+ * SVSM_CORE_REMAP_CA call:
+ * RAX = 0 (Protocol=0, CallID=0)
+ * RCX = New CA GPA
+ */
+ call.caa = svsm_get_caa();
+ call.rax = SVSM_CORE_CALL(SVSM_CORE_REMAP_CA);
+ call.rcx = pa;
+ ret = svsm_perform_call_protocol(&call);
+ if (ret)
+ panic("Can't remap the SVSM CA, ret=%d, rax_out=0x%llx\n", ret, call.rax_out);
+
+ RIP_REL_REF(boot_svsm_caa) = (struct svsm_ca *)pa;
+ RIP_REL_REF(boot_svsm_caa_pa) = pa;
+}
+
bool __head snp_init(struct boot_params *bp)
{
struct cc_blob_sev_info *cc_info;
@@ -2108,6 +2302,8 @@ bool __head snp_init(struct boot_params *bp)
setup_cpuid_table(cc_info);
+ svsm_setup(cc_info);
+
/*
* The CC blob will be used later to access the secrets page. Cache
* it here like the boot kernel does.
@@ -2156,23 +2352,27 @@ static void dump_cpuid_table(void)
* expected, but that initialization happens too early in boot to print any
* sort of indicator, and there's not really any other good place to do it,
* so do it here.
+ *
+ * If running as an SNP guest, report the current VM privilege level (VMPL).
*/
-static int __init report_cpuid_table(void)
+static int __init report_snp_info(void)
{
const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
- if (!cpuid_table->count)
- return 0;
+ if (cpuid_table->count) {
+ pr_info("Using SNP CPUID table, %d entries present.\n",
+ cpuid_table->count);
- pr_info("Using SNP CPUID table, %d entries present.\n",
- cpuid_table->count);
+ if (sev_cfg.debug)
+ dump_cpuid_table();
+ }
- if (sev_cfg.debug)
- dump_cpuid_table();
+ if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ pr_info("SNP running at VMPL%u.\n", snp_vmpl);
return 0;
}
-arch_initcall(report_cpuid_table);
+arch_initcall(report_snp_info);
static int __init init_sev_config(char *str)
{
@@ -2191,6 +2391,56 @@ static int __init init_sev_config(char *str)
}
__setup("sev=", init_sev_config);
+static void update_attest_input(struct svsm_call *call, struct svsm_attest_call *input)
+{
+ /* If (new) lengths have been returned, propagate them up */
+ if (call->rcx_out != call->rcx)
+ input->manifest_buf.len = call->rcx_out;
+
+ if (call->rdx_out != call->rdx)
+ input->certificates_buf.len = call->rdx_out;
+
+ if (call->r8_out != call->r8)
+ input->report_buf.len = call->r8_out;
+}
+
+int snp_issue_svsm_attest_req(u64 call_id, struct svsm_call *call,
+ struct svsm_attest_call *input)
+{
+ struct svsm_attest_call *ac;
+ unsigned long flags;
+ u64 attest_call_pa;
+ int ret;
+
+ if (!snp_vmpl)
+ return -EINVAL;
+
+ local_irq_save(flags);
+
+ call->caa = svsm_get_caa();
+
+ ac = (struct svsm_attest_call *)call->caa->svsm_buffer;
+ attest_call_pa = svsm_get_caa_pa() + offsetof(struct svsm_ca, svsm_buffer);
+
+ *ac = *input;
+
+ /*
+ * Set input registers for the request and set RDX and R8 to known
+ * values in order to detect length values being returned in them.
+ */
+ call->rax = call_id;
+ call->rcx = attest_call_pa;
+ call->rdx = -1;
+ call->r8 = -1;
+ ret = svsm_perform_call_protocol(call);
+ update_attest_input(call, input);
+
+ local_irq_restore(flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(snp_issue_svsm_attest_req);
+
int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio)
{
struct ghcb_state state;
@@ -2299,3 +2549,58 @@ void sev_show_status(void)
}
pr_cont("\n");
}
+
+void __init snp_update_svsm_ca(void)
+{
+ if (!snp_vmpl)
+ return;
+
+ /* Update the CAA to a proper kernel address */
+ boot_svsm_caa = &boot_svsm_ca_page;
+}
+
+#ifdef CONFIG_SYSFS
+static ssize_t vmpl_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%d\n", snp_vmpl);
+}
+
+static struct kobj_attribute vmpl_attr = __ATTR_RO(vmpl);
+
+static struct attribute *vmpl_attrs[] = {
+ &vmpl_attr.attr,
+ NULL
+};
+
+static struct attribute_group sev_attr_group = {
+ .attrs = vmpl_attrs,
+};
+
+static int __init sev_sysfs_init(void)
+{
+ struct kobject *sev_kobj;
+ struct device *dev_root;
+ int ret;
+
+ if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ return -ENODEV;
+
+ dev_root = bus_get_dev_root(&cpu_subsys);
+ if (!dev_root)
+ return -ENODEV;
+
+ sev_kobj = kobject_create_and_add("sev", &dev_root->kobj);
+ put_device(dev_root);
+
+ if (!sev_kobj)
+ return -ENOMEM;
+
+ ret = sysfs_create_group(sev_kobj, &sev_attr_group);
+ if (ret)
+ kobject_put(sev_kobj);
+
+ return ret;
+}
+arch_initcall(sev_sysfs_init);
+#endif // CONFIG_SYSFS
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/coco/sev/shared.c
index b4f8fa0f722c..71de53194089 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/coco/sev/shared.c
@@ -21,8 +21,30 @@
#define WARN(condition, format...) (!!(condition))
#define sev_printk(fmt, ...)
#define sev_printk_rtl(fmt, ...)
+#undef vc_forward_exception
+#define vc_forward_exception(c) panic("SNP: Hypervisor requested exception\n")
#endif
+/*
+ * SVSM related information:
+ * When running under an SVSM, the VMPL that Linux is executing at must be
+ * non-zero. The VMPL is therefore used to indicate the presence of an SVSM.
+ *
+ * During boot, the page tables are set up as identity mapped and later
+ * changed to use kernel virtual addresses. Maintain separate virtual and
+ * physical addresses for the CAA to allow SVSM functions to be used during
+ * early boot, both with identity mapped virtual addresses and proper kernel
+ * virtual addresses.
+ */
+u8 snp_vmpl __ro_after_init;
+EXPORT_SYMBOL_GPL(snp_vmpl);
+static struct svsm_ca *boot_svsm_caa __ro_after_init;
+static u64 boot_svsm_caa_pa __ro_after_init;
+
+static struct svsm_ca *svsm_get_caa(void);
+static u64 svsm_get_caa_pa(void);
+static int svsm_perform_call_protocol(struct svsm_call *call);
+
/* I/O parameters for CPUID-related helpers */
struct cpuid_leaf {
u32 fn;
@@ -229,6 +251,126 @@ static enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt
return ES_VMM_ERROR;
}
+static inline int svsm_process_result_codes(struct svsm_call *call)
+{
+ switch (call->rax_out) {
+ case SVSM_SUCCESS:
+ return 0;
+ case SVSM_ERR_INCOMPLETE:
+ case SVSM_ERR_BUSY:
+ return -EAGAIN;
+ default:
+ return -EINVAL;
+ }
+}
+
+/*
+ * Issue a VMGEXIT to call the SVSM:
+ * - Load the SVSM register state (RAX, RCX, RDX, R8 and R9)
+ * - Set the CA call pending field to 1
+ * - Issue VMGEXIT
+ * - Save the SVSM return register state (RAX, RCX, RDX, R8 and R9)
+ * - Perform atomic exchange of the CA call pending field
+ *
+ * - See the "Secure VM Service Module for SEV-SNP Guests" specification for
+ * details on the calling convention.
+ * - The calling convention loosely follows the Microsoft X64 calling
+ * convention by putting arguments in RCX, RDX, R8 and R9.
+ * - RAX specifies the SVSM protocol/callid as input and the return code
+ * as output.
+ */
+static __always_inline void svsm_issue_call(struct svsm_call *call, u8 *pending)
+{
+ register unsigned long rax asm("rax") = call->rax;
+ register unsigned long rcx asm("rcx") = call->rcx;
+ register unsigned long rdx asm("rdx") = call->rdx;
+ register unsigned long r8 asm("r8") = call->r8;
+ register unsigned long r9 asm("r9") = call->r9;
+
+ call->caa->call_pending = 1;
+
+ asm volatile("rep; vmmcall\n\t"
+ : "+r" (rax), "+r" (rcx), "+r" (rdx), "+r" (r8), "+r" (r9)
+ : : "memory");
+
+ *pending = xchg(&call->caa->call_pending, *pending);
+
+ call->rax_out = rax;
+ call->rcx_out = rcx;
+ call->rdx_out = rdx;
+ call->r8_out = r8;
+ call->r9_out = r9;
+}
+
+static int svsm_perform_msr_protocol(struct svsm_call *call)
+{
+ u8 pending = 0;
+ u64 val, resp;
+
+ /*
+ * When using the MSR protocol, be sure to save and restore
+ * the current MSR value.
+ */
+ val = sev_es_rd_ghcb_msr();
+
+ sev_es_wr_ghcb_msr(GHCB_MSR_VMPL_REQ_LEVEL(0));
+
+ svsm_issue_call(call, &pending);
+
+ resp = sev_es_rd_ghcb_msr();
+
+ sev_es_wr_ghcb_msr(val);
+
+ if (pending)
+ return -EINVAL;
+
+ if (GHCB_RESP_CODE(resp) != GHCB_MSR_VMPL_RESP)
+ return -EINVAL;
+
+ if (GHCB_MSR_VMPL_RESP_VAL(resp))
+ return -EINVAL;
+
+ return svsm_process_result_codes(call);
+}
+
+static int svsm_perform_ghcb_protocol(struct ghcb *ghcb, struct svsm_call *call)
+{
+ struct es_em_ctxt ctxt;
+ u8 pending = 0;
+
+ vc_ghcb_invalidate(ghcb);
+
+ /*
+ * Fill in protocol and format specifiers. This can be called very early
+ * in the boot, so use rip-relative references as needed.
+ */
+ ghcb->protocol_version = RIP_REL_REF(ghcb_version);
+ ghcb->ghcb_usage = GHCB_DEFAULT_USAGE;
+
+ ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_SNP_RUN_VMPL);
+ ghcb_set_sw_exit_info_1(ghcb, 0);
+ ghcb_set_sw_exit_info_2(ghcb, 0);
+
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+
+ svsm_issue_call(call, &pending);
+
+ if (pending)
+ return -EINVAL;
+
+ switch (verify_exception_info(ghcb, &ctxt)) {
+ case ES_OK:
+ break;
+ case ES_EXCEPTION:
+ vc_forward_exception(&ctxt);
+ fallthrough;
+ default:
+ return -EINVAL;
+ }
+
+ return svsm_process_result_codes(call);
+}
+
static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
struct es_em_ctxt *ctxt,
u64 exit_code, u64 exit_info_1,
@@ -1079,38 +1221,268 @@ static void __head setup_cpuid_table(const struct cc_blob_sev_info *cc_info)
}
}
-static void pvalidate_pages(struct snp_psc_desc *desc)
+static inline void __pval_terminate(u64 pfn, bool action, unsigned int page_size,
+ int ret, u64 svsm_ret)
+{
+ WARN(1, "PVALIDATE failure: pfn: 0x%llx, action: %u, size: %u, ret: %d, svsm_ret: 0x%llx\n",
+ pfn, action, page_size, ret, svsm_ret);
+
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE);
+}
+
+static void svsm_pval_terminate(struct svsm_pvalidate_call *pc, int ret, u64 svsm_ret)
+{
+ unsigned int page_size;
+ bool action;
+ u64 pfn;
+
+ pfn = pc->entry[pc->cur_index].pfn;
+ action = pc->entry[pc->cur_index].action;
+ page_size = pc->entry[pc->cur_index].page_size;
+
+ __pval_terminate(pfn, action, page_size, ret, svsm_ret);
+}
+
+static void svsm_pval_4k_page(unsigned long paddr, bool validate)
+{
+ struct svsm_pvalidate_call *pc;
+ struct svsm_call call = {};
+ unsigned long flags;
+ u64 pc_pa;
+ int ret;
+
+ /*
+ * This can be called very early in the boot, use native functions in
+ * order to avoid paravirt issues.
+ */
+ flags = native_local_irq_save();
+
+ call.caa = svsm_get_caa();
+
+ pc = (struct svsm_pvalidate_call *)call.caa->svsm_buffer;
+ pc_pa = svsm_get_caa_pa() + offsetof(struct svsm_ca, svsm_buffer);
+
+ pc->num_entries = 1;
+ pc->cur_index = 0;
+ pc->entry[0].page_size = RMP_PG_SIZE_4K;
+ pc->entry[0].action = validate;
+ pc->entry[0].ignore_cf = 0;
+ pc->entry[0].pfn = paddr >> PAGE_SHIFT;
+
+ /* Protocol 0, Call ID 1 */
+ call.rax = SVSM_CORE_CALL(SVSM_CORE_PVALIDATE);
+ call.rcx = pc_pa;
+
+ ret = svsm_perform_call_protocol(&call);
+ if (ret)
+ svsm_pval_terminate(pc, ret, call.rax_out);
+
+ native_local_irq_restore(flags);
+}
+
+static void pvalidate_4k_page(unsigned long vaddr, unsigned long paddr, bool validate)
+{
+ int ret;
+
+ /*
+ * This can be called very early during boot, so use rIP-relative
+ * references as needed.
+ */
+ if (RIP_REL_REF(snp_vmpl)) {
+ svsm_pval_4k_page(paddr, validate);
+ } else {
+ ret = pvalidate(vaddr, RMP_PG_SIZE_4K, validate);
+ if (ret)
+ __pval_terminate(PHYS_PFN(paddr), validate, RMP_PG_SIZE_4K, ret, 0);
+ }
+}
+
+static void pval_pages(struct snp_psc_desc *desc)
{
struct psc_entry *e;
unsigned long vaddr;
unsigned int size;
unsigned int i;
bool validate;
+ u64 pfn;
int rc;
for (i = 0; i <= desc->hdr.end_entry; i++) {
e = &desc->entries[i];
- vaddr = (unsigned long)pfn_to_kaddr(e->gfn);
+ pfn = e->gfn;
+ vaddr = (unsigned long)pfn_to_kaddr(pfn);
size = e->pagesize ? RMP_PG_SIZE_2M : RMP_PG_SIZE_4K;
validate = e->operation == SNP_PAGE_STATE_PRIVATE;
rc = pvalidate(vaddr, size, validate);
+ if (!rc)
+ continue;
+
if (rc == PVALIDATE_FAIL_SIZEMISMATCH && size == RMP_PG_SIZE_2M) {
unsigned long vaddr_end = vaddr + PMD_SIZE;
- for (; vaddr < vaddr_end; vaddr += PAGE_SIZE) {
+ for (; vaddr < vaddr_end; vaddr += PAGE_SIZE, pfn++) {
rc = pvalidate(vaddr, RMP_PG_SIZE_4K, validate);
if (rc)
- break;
+ __pval_terminate(pfn, validate, RMP_PG_SIZE_4K, rc, 0);
}
+ } else {
+ __pval_terminate(pfn, validate, size, rc, 0);
}
+ }
+}
+
+static u64 svsm_build_ca_from_pfn_range(u64 pfn, u64 pfn_end, bool action,
+ struct svsm_pvalidate_call *pc)
+{
+ struct svsm_pvalidate_entry *pe;
+
+ /* Nothing in the CA yet */
+ pc->num_entries = 0;
+ pc->cur_index = 0;
+
+ pe = &pc->entry[0];
+
+ while (pfn < pfn_end) {
+ pe->page_size = RMP_PG_SIZE_4K;
+ pe->action = action;
+ pe->ignore_cf = 0;
+ pe->pfn = pfn;
+
+ pe++;
+ pfn++;
+
+ pc->num_entries++;
+ if (pc->num_entries == SVSM_PVALIDATE_MAX_COUNT)
+ break;
+ }
+
+ return pfn;
+}
+
+static int svsm_build_ca_from_psc_desc(struct snp_psc_desc *desc, unsigned int desc_entry,
+ struct svsm_pvalidate_call *pc)
+{
+ struct svsm_pvalidate_entry *pe;
+ struct psc_entry *e;
+
+ /* Nothing in the CA yet */
+ pc->num_entries = 0;
+ pc->cur_index = 0;
+
+ pe = &pc->entry[0];
+ e = &desc->entries[desc_entry];
+
+ while (desc_entry <= desc->hdr.end_entry) {
+ pe->page_size = e->pagesize ? RMP_PG_SIZE_2M : RMP_PG_SIZE_4K;
+ pe->action = e->operation == SNP_PAGE_STATE_PRIVATE;
+ pe->ignore_cf = 0;
+ pe->pfn = e->gfn;
+
+ pe++;
+ e++;
+
+ desc_entry++;
+ pc->num_entries++;
+ if (pc->num_entries == SVSM_PVALIDATE_MAX_COUNT)
+ break;
+ }
+
+ return desc_entry;
+}
+
+static void svsm_pval_pages(struct snp_psc_desc *desc)
+{
+ struct svsm_pvalidate_entry pv_4k[VMGEXIT_PSC_MAX_ENTRY];
+ unsigned int i, pv_4k_count = 0;
+ struct svsm_pvalidate_call *pc;
+ struct svsm_call call = {};
+ unsigned long flags;
+ bool action;
+ u64 pc_pa;
+ int ret;
+
+ /*
+ * This can be called very early in the boot, use native functions in
+ * order to avoid paravirt issues.
+ */
+ flags = native_local_irq_save();
+
+ /*
+ * The SVSM calling area (CA) can support processing 510 entries at a
+ * time. Loop through the Page State Change descriptor until the CA is
+ * full or the last entry in the descriptor is reached, at which time
+ * the SVSM is invoked. This repeats until all entries in the descriptor
+ * are processed.
+ */
+ call.caa = svsm_get_caa();
+
+ pc = (struct svsm_pvalidate_call *)call.caa->svsm_buffer;
+ pc_pa = svsm_get_caa_pa() + offsetof(struct svsm_ca, svsm_buffer);
+
+ /* Protocol 0, Call ID 1 */
+ call.rax = SVSM_CORE_CALL(SVSM_CORE_PVALIDATE);
+ call.rcx = pc_pa;
+
+ for (i = 0; i <= desc->hdr.end_entry;) {
+ i = svsm_build_ca_from_psc_desc(desc, i, pc);
+
+ do {
+ ret = svsm_perform_call_protocol(&call);
+ if (!ret)
+ continue;
+
+ /*
+ * Check if the entry failed because of an RMP mismatch (a
+ * PVALIDATE at 2M was requested, but the page is mapped in
+ * the RMP as 4K).
+ */
- if (rc) {
- WARN(1, "Failed to validate address 0x%lx ret %d", vaddr, rc);
- sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE);
+ if (call.rax_out == SVSM_PVALIDATE_FAIL_SIZEMISMATCH &&
+ pc->entry[pc->cur_index].page_size == RMP_PG_SIZE_2M) {
+ /* Save this entry for post-processing at 4K */
+ pv_4k[pv_4k_count++] = pc->entry[pc->cur_index];
+
+ /* Skip to the next one unless at the end of the list */
+ pc->cur_index++;
+ if (pc->cur_index < pc->num_entries)
+ ret = -EAGAIN;
+ else
+ ret = 0;
+ }
+ } while (ret == -EAGAIN);
+
+ if (ret)
+ svsm_pval_terminate(pc, ret, call.rax_out);
+ }
+
+ /* Process any entries that failed to be validated at 2M and validate them at 4K */
+ for (i = 0; i < pv_4k_count; i++) {
+ u64 pfn, pfn_end;
+
+ action = pv_4k[i].action;
+ pfn = pv_4k[i].pfn;
+ pfn_end = pfn + 512;
+
+ while (pfn < pfn_end) {
+ pfn = svsm_build_ca_from_pfn_range(pfn, pfn_end, action, pc);
+
+ ret = svsm_perform_call_protocol(&call);
+ if (ret)
+ svsm_pval_terminate(pc, ret, call.rax_out);
}
}
+
+ native_local_irq_restore(flags);
+}
+
+static void pvalidate_pages(struct snp_psc_desc *desc)
+{
+ if (snp_vmpl)
+ svsm_pval_pages(desc);
+ else
+ pval_pages(desc);
}
static int vmgexit_psc(struct ghcb *ghcb, struct snp_psc_desc *desc)
@@ -1269,3 +1641,77 @@ static enum es_result vc_check_opcode_bytes(struct es_em_ctxt *ctxt,
return ES_UNSUPPORTED;
}
+
+/*
+ * Maintain the GPA of the SVSM Calling Area (CA) in order to utilize the SVSM
+ * services needed when not running in VMPL0.
+ */
+static bool __head svsm_setup_ca(const struct cc_blob_sev_info *cc_info)
+{
+ struct snp_secrets_page *secrets_page;
+ struct snp_cpuid_table *cpuid_table;
+ unsigned int i;
+ u64 caa;
+
+ BUILD_BUG_ON(sizeof(*secrets_page) != PAGE_SIZE);
+
+ /*
+ * Check if running at VMPL0.
+ *
+ * Use RMPADJUST (see the rmpadjust() function for a description of what
+ * the instruction does) to update the VMPL1 permissions of a page. If
+ * the guest is running at VMPL0, this will succeed and implies there is
+ * no SVSM. If the guest is running at any other VMPL, this will fail.
+ * Linux SNP guests only ever run at a single VMPL level so permission mask
+ * changes of a lesser-privileged VMPL are a don't-care.
+ *
+ * Use a rip-relative reference to obtain the proper address, since this
+ * routine is running identity mapped when called, both by the decompressor
+ * code and the early kernel code.
+ */
+ if (!rmpadjust((unsigned long)&RIP_REL_REF(boot_ghcb_page), RMP_PG_SIZE_4K, 1))
+ return false;
+
+ /*
+ * Not running at VMPL0, ensure everything has been properly supplied
+ * for running under an SVSM.
+ */
+ if (!cc_info || !cc_info->secrets_phys || cc_info->secrets_len != PAGE_SIZE)
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SECRETS_PAGE);
+
+ secrets_page = (struct snp_secrets_page *)cc_info->secrets_phys;
+ if (!secrets_page->svsm_size)
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_NO_SVSM);
+
+ if (!secrets_page->svsm_guest_vmpl)
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SVSM_VMPL0);
+
+ RIP_REL_REF(snp_vmpl) = secrets_page->svsm_guest_vmpl;
+
+ caa = secrets_page->svsm_caa;
+
+ /*
+ * An open-coded PAGE_ALIGNED() in order to avoid including
+ * kernel-proper headers into the decompressor.
+ */
+ if (caa & (PAGE_SIZE - 1))
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SVSM_CAA);
+
+ /*
+ * The CA is identity mapped when this routine is called, both by the
+ * decompressor code and the early kernel code.
+ */
+ RIP_REL_REF(boot_svsm_caa) = (struct svsm_ca *)caa;
+ RIP_REL_REF(boot_svsm_caa_pa) = caa;
+
+ /* Advertise the SVSM presence via CPUID. */
+ cpuid_table = (struct snp_cpuid_table *)snp_cpuid_get_table();
+ for (i = 0; i < cpuid_table->count; i++) {
+ struct snp_cpuid_fn *fn = &cpuid_table->fn[i];
+
+ if (fn->eax_in == 0x8000001f)
+ fn->eax |= BIT(28);
+ }
+
+ return true;
+}
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index a1dd81027c2d..b51e88d01b21 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -446,6 +446,7 @@
#define X86_FEATURE_V_TSC_AUX (19*32+ 9) /* Virtual TSC_AUX */
#define X86_FEATURE_SME_COHERENT (19*32+10) /* AMD hardware-enforced cache coherency */
#define X86_FEATURE_DEBUG_SWAP (19*32+14) /* "debug_swap" AMD SEV-ES full debug state swap support */
+#define X86_FEATURE_SVSM (19*32+28) /* "svsm" SVSM present */
/* AMD-defined Extended Feature 2 EAX, CPUID level 0x80000021 (EAX), word 20 */
#define X86_FEATURE_NO_NESTED_DATA_BP (20*32+ 0) /* No Nested Data Breakpoints */
diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
index 8c5ae649d2df..cf7fc2b8e3ce 100644
--- a/arch/x86/include/asm/irqflags.h
+++ b/arch/x86/include/asm/irqflags.h
@@ -54,6 +54,26 @@ static __always_inline void native_halt(void)
asm volatile("hlt": : :"memory");
}
+static __always_inline int native_irqs_disabled_flags(unsigned long flags)
+{
+ return !(flags & X86_EFLAGS_IF);
+}
+
+static __always_inline unsigned long native_local_irq_save(void)
+{
+ unsigned long flags = native_save_fl();
+
+ native_irq_disable();
+
+ return flags;
+}
+
+static __always_inline void native_local_irq_restore(unsigned long flags)
+{
+ if (!native_irqs_disabled_flags(flags))
+ native_irq_enable();
+}
+
#endif
#ifdef CONFIG_PARAVIRT_XXL
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 3cb8dd6311c3..01342963011e 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -660,6 +660,8 @@
#define MSR_AMD64_RMP_BASE 0xc0010132
#define MSR_AMD64_RMP_END 0xc0010133
+#define MSR_SVSM_CAA 0xc001f000
+
/* AMD Collaborative Processor Performance Control MSRs */
#define MSR_AMD_CPPC_CAP1 0xc00102b0
#define MSR_AMD_CPPC_ENABLE 0xc00102b1
diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h
index 5a8246dd532f..e90d403f2068 100644
--- a/arch/x86/include/asm/sev-common.h
+++ b/arch/x86/include/asm/sev-common.h
@@ -98,6 +98,19 @@ enum psc_op {
/* GHCBData[63:32] */ \
(((u64)(val) & GENMASK_ULL(63, 32)) >> 32)
+/* GHCB Run at VMPL Request/Response */
+#define GHCB_MSR_VMPL_REQ 0x016
+#define GHCB_MSR_VMPL_REQ_LEVEL(v) \
+ /* GHCBData[39:32] */ \
+ (((u64)(v) & GENMASK_ULL(7, 0) << 32) | \
+ /* GHCBDdata[11:0] */ \
+ GHCB_MSR_VMPL_REQ)
+
+#define GHCB_MSR_VMPL_RESP 0x017
+#define GHCB_MSR_VMPL_RESP_VAL(v) \
+ /* GHCBData[63:32] */ \
+ (((u64)(v) & GENMASK_ULL(63, 32)) >> 32)
+
/* GHCB Hypervisor Feature Request/Response */
#define GHCB_MSR_HV_FT_REQ 0x080
#define GHCB_MSR_HV_FT_RESP 0x081
@@ -109,6 +122,7 @@ enum psc_op {
#define GHCB_HV_FT_SNP BIT_ULL(0)
#define GHCB_HV_FT_SNP_AP_CREATION BIT_ULL(1)
+#define GHCB_HV_FT_SNP_MULTI_VMPL BIT_ULL(5)
/*
* SNP Page State Change NAE event
@@ -163,6 +177,10 @@ struct snp_psc_desc {
#define GHCB_TERM_NOT_VMPL0 3 /* SNP guest is not running at VMPL-0 */
#define GHCB_TERM_CPUID 4 /* CPUID-validation failure */
#define GHCB_TERM_CPUID_HV 5 /* CPUID failure during hypervisor fallback */
+#define GHCB_TERM_SECRETS_PAGE 6 /* Secrets page failure */
+#define GHCB_TERM_NO_SVSM 7 /* SVSM is not advertised in the secrets page */
+#define GHCB_TERM_SVSM_VMPL0 8 /* SVSM is present but has set VMPL to 0 */
+#define GHCB_TERM_SVSM_CAA 9 /* SVSM is present but CAA is not page aligned */
#define GHCB_RESP_CODE(v) ((v) & GHCB_MSR_INFO_MASK)
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index ca20cc4e5826..ac5886ce252e 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -152,10 +152,119 @@ struct snp_secrets_page {
u8 vmpck2[VMPCK_KEY_LEN];
u8 vmpck3[VMPCK_KEY_LEN];
struct secrets_os_area os_area;
- u8 rsvd3[3840];
+
+ u8 vmsa_tweak_bitmap[64];
+
+ /* SVSM fields */
+ u64 svsm_base;
+ u64 svsm_size;
+ u64 svsm_caa;
+ u32 svsm_max_version;
+ u8 svsm_guest_vmpl;
+ u8 rsvd3[3];
+
+ /* Remainder of page */
+ u8 rsvd4[3744];
} __packed;
+/*
+ * The SVSM Calling Area (CA) related structures.
+ */
+struct svsm_ca {
+ u8 call_pending;
+ u8 mem_available;
+ u8 rsvd1[6];
+
+ u8 svsm_buffer[PAGE_SIZE - 8];
+};
+
+#define SVSM_SUCCESS 0
+#define SVSM_ERR_INCOMPLETE 0x80000000
+#define SVSM_ERR_UNSUPPORTED_PROTOCOL 0x80000001
+#define SVSM_ERR_UNSUPPORTED_CALL 0x80000002
+#define SVSM_ERR_INVALID_ADDRESS 0x80000003
+#define SVSM_ERR_INVALID_FORMAT 0x80000004
+#define SVSM_ERR_INVALID_PARAMETER 0x80000005
+#define SVSM_ERR_INVALID_REQUEST 0x80000006
+#define SVSM_ERR_BUSY 0x80000007
+#define SVSM_PVALIDATE_FAIL_SIZEMISMATCH 0x80001006
+
+/*
+ * The SVSM PVALIDATE related structures
+ */
+struct svsm_pvalidate_entry {
+ u64 page_size : 2,
+ action : 1,
+ ignore_cf : 1,
+ rsvd : 8,
+ pfn : 52;
+};
+
+struct svsm_pvalidate_call {
+ u16 num_entries;
+ u16 cur_index;
+
+ u8 rsvd1[4];
+
+ struct svsm_pvalidate_entry entry[];
+};
+
+#define SVSM_PVALIDATE_MAX_COUNT ((sizeof_field(struct svsm_ca, svsm_buffer) - \
+ offsetof(struct svsm_pvalidate_call, entry)) / \
+ sizeof(struct svsm_pvalidate_entry))
+
+/*
+ * The SVSM Attestation related structures
+ */
+struct svsm_loc_entry {
+ u64 pa;
+ u32 len;
+ u8 rsvd[4];
+};
+
+struct svsm_attest_call {
+ struct svsm_loc_entry report_buf;
+ struct svsm_loc_entry nonce;
+ struct svsm_loc_entry manifest_buf;
+ struct svsm_loc_entry certificates_buf;
+
+ /* For attesting a single service */
+ u8 service_guid[16];
+ u32 service_manifest_ver;
+ u8 rsvd[4];
+};
+
+/*
+ * SVSM protocol structure
+ */
+struct svsm_call {
+ struct svsm_ca *caa;
+ u64 rax;
+ u64 rcx;
+ u64 rdx;
+ u64 r8;
+ u64 r9;
+ u64 rax_out;
+ u64 rcx_out;
+ u64 rdx_out;
+ u64 r8_out;
+ u64 r9_out;
+};
+
+#define SVSM_CORE_CALL(x) ((0ULL << 32) | (x))
+#define SVSM_CORE_REMAP_CA 0
+#define SVSM_CORE_PVALIDATE 1
+#define SVSM_CORE_CREATE_VCPU 2
+#define SVSM_CORE_DELETE_VCPU 3
+
+#define SVSM_ATTEST_CALL(x) ((1ULL << 32) | (x))
+#define SVSM_ATTEST_SERVICES 0
+#define SVSM_ATTEST_SINGLE_SERVICE 1
+
#ifdef CONFIG_AMD_MEM_ENCRYPT
+
+extern u8 snp_vmpl;
+
extern void __sev_es_ist_enter(struct pt_regs *regs);
extern void __sev_es_ist_exit(void);
static __always_inline void sev_es_ist_enter(struct pt_regs *regs)
@@ -181,6 +290,14 @@ static __always_inline void sev_es_nmi_complete(void)
extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
extern void sev_enable(struct boot_params *bp);
+/*
+ * RMPADJUST modifies the RMP permissions of a page of a lesser-
+ * privileged (numerically higher) VMPL.
+ *
+ * If the guest is running at a higher-privilege than the privilege
+ * level the instruction is targeting, the instruction will succeed,
+ * otherwise, it will fail.
+ */
static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs)
{
int rc;
@@ -225,11 +342,16 @@ bool snp_init(struct boot_params *bp);
void __noreturn snp_abort(void);
void snp_dmi_setup(void);
int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio);
+int snp_issue_svsm_attest_req(u64 call_id, struct svsm_call *call, struct svsm_attest_call *input);
void snp_accept_memory(phys_addr_t start, phys_addr_t end);
u64 snp_get_unsupported_features(u64 status);
u64 sev_get_status(void);
void sev_show_status(void);
-#else
+void snp_update_svsm_ca(void);
+
+#else /* !CONFIG_AMD_MEM_ENCRYPT */
+
+#define snp_vmpl 0
static inline void sev_es_ist_enter(struct pt_regs *regs) { }
static inline void sev_es_ist_exit(void) { }
static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; }
@@ -253,12 +375,17 @@ static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *in
{
return -ENOTTY;
}
-
+static inline int snp_issue_svsm_attest_req(u64 call_id, struct svsm_call *call, struct svsm_attest_call *input)
+{
+ return -ENOTTY;
+}
static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { }
static inline u64 snp_get_unsupported_features(u64 status) { return 0; }
static inline u64 sev_get_status(void) { return 0; }
static inline void sev_show_status(void) { }
-#endif
+static inline void snp_update_svsm_ca(void) { }
+
+#endif /* CONFIG_AMD_MEM_ENCRYPT */
#ifdef CONFIG_KVM_AMD_SEV
bool snp_probe_rmptable_info(void);
diff --git a/arch/x86/include/uapi/asm/svm.h b/arch/x86/include/uapi/asm/svm.h
index 80e1df482337..1814b413fd57 100644
--- a/arch/x86/include/uapi/asm/svm.h
+++ b/arch/x86/include/uapi/asm/svm.h
@@ -115,6 +115,7 @@
#define SVM_VMGEXIT_AP_CREATE_ON_INIT 0
#define SVM_VMGEXIT_AP_CREATE 1
#define SVM_VMGEXIT_AP_DESTROY 2
+#define SVM_VMGEXIT_SNP_RUN_VMPL 0x80000018
#define SVM_VMGEXIT_HV_FEATURES 0x8000fffd
#define SVM_VMGEXIT_TERM_REQUEST 0x8000fffe
#define SVM_VMGEXIT_TERM_REASON(reason_set, reason_code) \
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 20a0dd51700a..a847180836e4 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -17,7 +17,6 @@ CFLAGS_REMOVE_ftrace.o = -pg
CFLAGS_REMOVE_early_printk.o = -pg
CFLAGS_REMOVE_head64.o = -pg
CFLAGS_REMOVE_head32.o = -pg
-CFLAGS_REMOVE_sev.o = -pg
CFLAGS_REMOVE_rethook.o = -pg
endif
@@ -26,19 +25,16 @@ KASAN_SANITIZE_dumpstack.o := n
KASAN_SANITIZE_dumpstack_$(BITS).o := n
KASAN_SANITIZE_stacktrace.o := n
KASAN_SANITIZE_paravirt.o := n
-KASAN_SANITIZE_sev.o := n
# With some compiler versions the generated code results in boot hangs, caused
# by several compilation units. To be safe, disable all instrumentation.
KCSAN_SANITIZE := n
KMSAN_SANITIZE_head$(BITS).o := n
KMSAN_SANITIZE_nmi.o := n
-KMSAN_SANITIZE_sev.o := n
# If instrumentation of the following files is enabled, boot hangs during
# first second.
KCOV_INSTRUMENT_head$(BITS).o := n
-KCOV_INSTRUMENT_sev.o := n
CFLAGS_irq.o := -I $(src)/../include/asm/trace
@@ -142,8 +138,6 @@ obj-$(CONFIG_UNWINDER_ORC) += unwind_orc.o
obj-$(CONFIG_UNWINDER_FRAME_POINTER) += unwind_frame.o
obj-$(CONFIG_UNWINDER_GUESS) += unwind_guess.o
-obj-$(CONFIG_AMD_MEM_ENCRYPT) += sev.o
-
obj-$(CONFIG_CFI_CLANG) += cfi.o
obj-$(CONFIG_CALL_THUNKS) += callthunks.o
diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c
index e7b67519ddb5..86a476a426c2 100644
--- a/arch/x86/mm/mem_encrypt_amd.c
+++ b/arch/x86/mm/mem_encrypt_amd.c
@@ -2,7 +2,7 @@
/*
* AMD Memory Encryption Support
*
- * Copyright (C) 2016 Advanced Micro Devices, Inc.
+ * Copyright (C) 2016-2024 Advanced Micro Devices, Inc.
*
* Author: Tom Lendacky <thomas.lendacky@amd.com>
*/
@@ -510,6 +510,12 @@ void __init sme_early_init(void)
*/
x86_init.resources.dmi_setup = snp_dmi_setup;
}
+
+ /*
+ * Switch the SVSM CA mapping (if active) from identity mapped to
+ * kernel mapped.
+ */
+ snp_update_svsm_ca();
}
void __init mem_encrypt_free_decrypted_mem(void)
diff --git a/arch/x86/virt/svm/sev.c b/arch/x86/virt/svm/sev.c
index 0ae10535c699..0ce17766c0e5 100644
--- a/arch/x86/virt/svm/sev.c
+++ b/arch/x86/virt/svm/sev.c
@@ -120,7 +120,7 @@ static __init void snp_enable(void *arg)
bool snp_probe_rmptable_info(void)
{
- u64 max_rmp_pfn, calc_rmp_sz, rmp_sz, rmp_base, rmp_end;
+ u64 rmp_sz, rmp_base, rmp_end;
rdmsrl(MSR_AMD64_RMP_BASE, rmp_base);
rdmsrl(MSR_AMD64_RMP_END, rmp_end);
@@ -137,28 +137,11 @@ bool snp_probe_rmptable_info(void)
rmp_sz = rmp_end - rmp_base + 1;
- /*
- * Calculate the amount the memory that must be reserved by the BIOS to
- * address the whole RAM, including the bookkeeping area. The RMP itself
- * must also be covered.
- */
- max_rmp_pfn = max_pfn;
- if (PHYS_PFN(rmp_end) > max_pfn)
- max_rmp_pfn = PHYS_PFN(rmp_end);
-
- calc_rmp_sz = (max_rmp_pfn << 4) + RMPTABLE_CPU_BOOKKEEPING_SZ;
-
- if (calc_rmp_sz > rmp_sz) {
- pr_err("Memory reserved for the RMP table does not cover full system RAM (expected 0x%llx got 0x%llx)\n",
- calc_rmp_sz, rmp_sz);
- return false;
- }
-
probed_rmp_base = rmp_base;
probed_rmp_size = rmp_sz;
pr_info("RMP table physical range [0x%016llx - 0x%016llx]\n",
- probed_rmp_base, probed_rmp_base + probed_rmp_size - 1);
+ rmp_base, rmp_end);
return true;
}
@@ -206,9 +189,8 @@ void __init snp_fixup_e820_tables(void)
*/
static int __init snp_rmptable_init(void)
{
+ u64 max_rmp_pfn, calc_rmp_sz, rmptable_size, rmp_end, val;
void *rmptable_start;
- u64 rmptable_size;
- u64 val;
if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP))
return 0;
@@ -219,10 +201,28 @@ static int __init snp_rmptable_init(void)
if (!probed_rmp_size)
goto nosnp;
+ rmp_end = probed_rmp_base + probed_rmp_size - 1;
+
+ /*
+ * Calculate the amount the memory that must be reserved by the BIOS to
+ * address the whole RAM, including the bookkeeping area. The RMP itself
+ * must also be covered.
+ */
+ max_rmp_pfn = max_pfn;
+ if (PFN_UP(rmp_end) > max_pfn)
+ max_rmp_pfn = PFN_UP(rmp_end);
+
+ calc_rmp_sz = (max_rmp_pfn << 4) + RMPTABLE_CPU_BOOKKEEPING_SZ;
+ if (calc_rmp_sz > probed_rmp_size) {
+ pr_err("Memory reserved for the RMP table does not cover full system RAM (expected 0x%llx got 0x%llx)\n",
+ calc_rmp_sz, probed_rmp_size);
+ goto nosnp;
+ }
+
rmptable_start = memremap(probed_rmp_base, probed_rmp_size, MEMREMAP_WB);
if (!rmptable_start) {
pr_err("Failed to map RMP table\n");
- return 1;
+ goto nosnp;
}
/*
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-11-24 14:17:01 +0000