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authorKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>2022-04-06 02:29:28 +0300
committerDave Hansen <dave.hansen@linux.intel.com>2022-04-07 08:27:52 -0700
commitcfb8ec7a31f234b4519c104f1cc9accbc8b393a9 (patch)
tree72f6fdeb556b0a02c7940f86114c607a9eae31cd /arch/x86/include
parent32e72854fa5fef6bc72e27c54f31897db9092acb (diff)
x86/tdx: Wire up KVM hypercalls
KVM hypercalls use the VMCALL or VMMCALL instructions. Although the ABI is similar, those instructions no longer function for TDX guests. Make vendor-specific TDVMCALLs instead of VMCALL. This enables TDX guests to run with KVM acting as the hypervisor. Among other things, KVM hypercall is used to send IPIs. Since the KVM driver can be built as a kernel module, export tdx_kvm_hypercall() to make the symbols visible to kvm.ko. Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20220405232939.73860-20-kirill.shutemov@linux.intel.com
Diffstat (limited to 'arch/x86/include')
-rw-r--r--arch/x86/include/asm/kvm_para.h22
-rw-r--r--arch/x86/include/asm/tdx.h11
2 files changed, 33 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
index 56935ebb1dfe..57bc74e112f2 100644
--- a/arch/x86/include/asm/kvm_para.h
+++ b/arch/x86/include/asm/kvm_para.h
@@ -7,6 +7,8 @@
#include <linux/interrupt.h>
#include <uapi/asm/kvm_para.h>
+#include <asm/tdx.h>
+
#ifdef CONFIG_KVM_GUEST
bool kvm_check_and_clear_guest_paused(void);
#else
@@ -32,6 +34,10 @@ static inline bool kvm_check_and_clear_guest_paused(void)
static inline long kvm_hypercall0(unsigned int nr)
{
long ret;
+
+ if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
+ return tdx_kvm_hypercall(nr, 0, 0, 0, 0);
+
asm volatile(KVM_HYPERCALL
: "=a"(ret)
: "a"(nr)
@@ -42,6 +48,10 @@ static inline long kvm_hypercall0(unsigned int nr)
static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
{
long ret;
+
+ if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
+ return tdx_kvm_hypercall(nr, p1, 0, 0, 0);
+
asm volatile(KVM_HYPERCALL
: "=a"(ret)
: "a"(nr), "b"(p1)
@@ -53,6 +63,10 @@ static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
unsigned long p2)
{
long ret;
+
+ if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
+ return tdx_kvm_hypercall(nr, p1, p2, 0, 0);
+
asm volatile(KVM_HYPERCALL
: "=a"(ret)
: "a"(nr), "b"(p1), "c"(p2)
@@ -64,6 +78,10 @@ static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
unsigned long p2, unsigned long p3)
{
long ret;
+
+ if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
+ return tdx_kvm_hypercall(nr, p1, p2, p3, 0);
+
asm volatile(KVM_HYPERCALL
: "=a"(ret)
: "a"(nr), "b"(p1), "c"(p2), "d"(p3)
@@ -76,6 +94,10 @@ static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
unsigned long p4)
{
long ret;
+
+ if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
+ return tdx_kvm_hypercall(nr, p1, p2, p3, p4);
+
asm volatile(KVM_HYPERCALL
: "=a"(ret)
: "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4)
diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
index 9ffd0d2e6e0f..020c81a7c729 100644
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -76,5 +76,16 @@ static inline bool tdx_early_handle_ve(struct pt_regs *regs) { return false; }
#endif /* CONFIG_INTEL_TDX_GUEST */
+#if defined(CONFIG_KVM_GUEST) && defined(CONFIG_INTEL_TDX_GUEST)
+long tdx_kvm_hypercall(unsigned int nr, unsigned long p1, unsigned long p2,
+ unsigned long p3, unsigned long p4);
+#else
+static inline long tdx_kvm_hypercall(unsigned int nr, unsigned long p1,
+ unsigned long p2, unsigned long p3,
+ unsigned long p4)
+{
+ return -ENODEV;
+}
+#endif /* CONFIG_INTEL_TDX_GUEST && CONFIG_KVM_GUEST */
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_X86_TDX_H */