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authorLinus Torvalds <torvalds@linux-foundation.org>2021-10-10 10:00:51 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-10-10 10:00:51 -0700
commitc22ccc4a3ef198752855f44e9279732260c889d5 (patch)
tree48e685f8eff9fbe0bbac122c3b2e49680f25a18f /arch/x86/kernel
parent7fd2bf83d59a2d32e0d596c5d3e623b9a0e7e2d5 (diff)
parentd298b03506d3e161f7492c440babb0bfae35e650 (diff)
Merge tag 'x86_urgent_for_v5.15_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov: - A FPU fix to properly handle invalid MXCSR values: 32-bit masks them out due to historical reasons and 64-bit kernels reject them - A fix to clear X86_FEATURE_SMAP when support for is not config-enabled - Three fixes correcting misspelled Kconfig symbols used in code - Two resctrl object cleanup fixes - Yet another attempt at fixing the neverending saga of botched x86 timers, this time because some incredibly smart hardware decides to turn off the HPET timer in a low power state - who cares if the OS is relying on it... - Check the full return value range of an SEV VMGEXIT call to determine whether it returned an error * tag 'x86_urgent_for_v5.15_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/fpu: Restore the masking out of reserved MXCSR bits x86/Kconfig: Correct reference to MWINCHIP3D x86/platform/olpc: Correct ifdef symbol to intended CONFIG_OLPC_XO15_SCI x86/entry: Clear X86_FEATURE_SMAP when CONFIG_X86_SMAP=n x86/entry: Correct reference to intended CONFIG_64_BIT x86/resctrl: Fix kfree() of the wrong type in domain_add_cpu() x86/resctrl: Free the ctrlval arrays when domain_setup_mon_state() fails x86/hpet: Use another crystalball to evaluate HPET usability x86/sev: Return an error on a returned non-zero SW_EXITINFO1[31:0]
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/cpu/common.c1
-rw-r--r--arch/x86/kernel/cpu/resctrl/core.c6
-rw-r--r--arch/x86/kernel/early-quirks.c6
-rw-r--r--arch/x86/kernel/fpu/signal.c11
-rw-r--r--arch/x86/kernel/hpet.c81
-rw-r--r--arch/x86/kernel/sev-shared.c2
6 files changed, 96 insertions, 11 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 0f8885949e8c..b3410f1ac217 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -326,6 +326,7 @@ static __always_inline void setup_smap(struct cpuinfo_x86 *c)
#ifdef CONFIG_X86_SMAP
cr4_set_bits(X86_CR4_SMAP);
#else
+ clear_cpu_cap(c, X86_FEATURE_SMAP);
cr4_clear_bits(X86_CR4_SMAP);
#endif
}
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 4b8813bafffd..bb1c3f5f60c8 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -527,12 +527,14 @@ static void domain_add_cpu(int cpu, struct rdt_resource *r)
rdt_domain_reconfigure_cdp(r);
if (r->alloc_capable && domain_setup_ctrlval(r, d)) {
- kfree(d);
+ kfree(hw_dom);
return;
}
if (r->mon_capable && domain_setup_mon_state(r, d)) {
- kfree(d);
+ kfree(hw_dom->ctrl_val);
+ kfree(hw_dom->mbps_val);
+ kfree(hw_dom);
return;
}
diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
index 38837dad46e6..391a4e2b8604 100644
--- a/arch/x86/kernel/early-quirks.c
+++ b/arch/x86/kernel/early-quirks.c
@@ -714,12 +714,6 @@ static struct chipset early_qrk[] __initdata = {
*/
{ PCI_VENDOR_ID_INTEL, 0x0f00,
PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, force_disable_hpet},
- { PCI_VENDOR_ID_INTEL, 0x3e20,
- PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, force_disable_hpet},
- { PCI_VENDOR_ID_INTEL, 0x3ec4,
- PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, force_disable_hpet},
- { PCI_VENDOR_ID_INTEL, 0x8a12,
- PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, force_disable_hpet},
{ PCI_VENDOR_ID_BROADCOM, 0x4331,
PCI_CLASS_NETWORK_OTHER, PCI_ANY_ID, 0, apple_airport_reset},
{}
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index 445c57c9c539..fa17a27390ab 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -379,9 +379,14 @@ static int __fpu_restore_sig(void __user *buf, void __user *buf_fx,
sizeof(fpu->state.fxsave)))
return -EFAULT;
- /* Reject invalid MXCSR values. */
- if (fpu->state.fxsave.mxcsr & ~mxcsr_feature_mask)
- return -EINVAL;
+ if (IS_ENABLED(CONFIG_X86_64)) {
+ /* Reject invalid MXCSR values. */
+ if (fpu->state.fxsave.mxcsr & ~mxcsr_feature_mask)
+ return -EINVAL;
+ } else {
+ /* Mask invalid bits out for historical reasons (broken hardware). */
+ fpu->state.fxsave.mxcsr &= ~mxcsr_feature_mask;
+ }
/* Enforce XFEATURE_MASK_FPSSE when XSAVE is enabled */
if (use_xsave())
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 42fc41dd0e1f..882213df3713 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -10,6 +10,7 @@
#include <asm/irq_remapping.h>
#include <asm/hpet.h>
#include <asm/time.h>
+#include <asm/mwait.h>
#undef pr_fmt
#define pr_fmt(fmt) "hpet: " fmt
@@ -916,6 +917,83 @@ static bool __init hpet_counting(void)
return false;
}
+static bool __init mwait_pc10_supported(void)
+{
+ unsigned int eax, ebx, ecx, mwait_substates;
+
+ if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
+ return false;
+
+ if (!cpu_feature_enabled(X86_FEATURE_MWAIT))
+ return false;
+
+ if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
+ return false;
+
+ cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
+
+ return (ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) &&
+ (ecx & CPUID5_ECX_INTERRUPT_BREAK) &&
+ (mwait_substates & (0xF << 28));
+}
+
+/*
+ * Check whether the system supports PC10. If so force disable HPET as that
+ * stops counting in PC10. This check is overbroad as it does not take any
+ * of the following into account:
+ *
+ * - ACPI tables
+ * - Enablement of intel_idle
+ * - Command line arguments which limit intel_idle C-state support
+ *
+ * That's perfectly fine. HPET is a piece of hardware designed by committee
+ * and the only reasons why it is still in use on modern systems is the
+ * fact that it is impossible to reliably query TSC and CPU frequency via
+ * CPUID or firmware.
+ *
+ * If HPET is functional it is useful for calibrating TSC, but this can be
+ * done via PMTIMER as well which seems to be the last remaining timer on
+ * X86/INTEL platforms that has not been completely wreckaged by feature
+ * creep.
+ *
+ * In theory HPET support should be removed altogether, but there are older
+ * systems out there which depend on it because TSC and APIC timer are
+ * dysfunctional in deeper C-states.
+ *
+ * It's only 20 years now that hardware people have been asked to provide
+ * reliable and discoverable facilities which can be used for timekeeping
+ * and per CPU timer interrupts.
+ *
+ * The probability that this problem is going to be solved in the
+ * forseeable future is close to zero, so the kernel has to be cluttered
+ * with heuristics to keep up with the ever growing amount of hardware and
+ * firmware trainwrecks. Hopefully some day hardware people will understand
+ * that the approach of "This can be fixed in software" is not sustainable.
+ * Hope dies last...
+ */
+static bool __init hpet_is_pc10_damaged(void)
+{
+ unsigned long long pcfg;
+
+ /* Check whether PC10 substates are supported */
+ if (!mwait_pc10_supported())
+ return false;
+
+ /* Check whether PC10 is enabled in PKG C-state limit */
+ rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, pcfg);
+ if ((pcfg & 0xF) < 8)
+ return false;
+
+ if (hpet_force_user) {
+ pr_warn("HPET force enabled via command line, but dysfunctional in PC10.\n");
+ return false;
+ }
+
+ pr_info("HPET dysfunctional in PC10. Force disabled.\n");
+ boot_hpet_disable = true;
+ return true;
+}
+
/**
* hpet_enable - Try to setup the HPET timer. Returns 1 on success.
*/
@@ -929,6 +1007,9 @@ int __init hpet_enable(void)
if (!is_hpet_capable())
return 0;
+ if (hpet_is_pc10_damaged())
+ return 0;
+
hpet_set_mapping();
if (!hpet_virt_address)
return 0;
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
index 9f90f460a28c..bf1033a62e48 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -130,6 +130,8 @@ static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
} else {
ret = ES_VMM_ERROR;
}
+ } else if (ghcb->save.sw_exit_info_1 & 0xffffffff) {
+ ret = ES_VMM_ERROR;
} else {
ret = ES_OK;
}