Modify following APIs for x86 implementation:
1) kvm_arch_main : Query the cpu vendor and cache the value in advance.
2) kvm_arch_post_vm_load: Populate cpu type in the guest memory so that
guest doesn't need to execute cpuid instruction again.
Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Vishal Annapurve <vannapurve@xxxxxxxxxx>
---
.../testing/selftests/kvm/lib/x86_64/processor.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index e22cfc4bf284..ac104653ab43 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -19,6 +19,7 @@
#define MAX_NR_CPUID_ENTRIES 100
vm_vaddr_t exception_handlers;
+static int is_cpu_amd = -1;
static void regs_dump(FILE *stream, struct kvm_regs *regs, uint8_t indent)
{
@@ -1019,7 +1020,7 @@ static bool cpu_vendor_string_is(const char *vendor)
bool is_intel_cpu(void)
{
- return cpu_vendor_string_is("GenuineIntel");
+ return (is_cpu_amd == 0);
}
/*
@@ -1027,7 +1028,7 @@ bool is_intel_cpu(void)
*/
bool is_amd_cpu(void)
{
- return cpu_vendor_string_is("AuthenticAMD");
+ return (is_cpu_amd == 1);
}
void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits)
@@ -1182,9 +1183,15 @@ uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2,
{
uint64_t r;
- asm volatile("vmcall"
+ if (is_amd_cpu())
+ asm volatile("vmmcall"
: "=a"(r)
: "a"(nr), "b"(a0), "c"(a1), "d"(a2), "S"(a3));
+ else
+ asm volatile("vmcall"
+ : "=a"(r)
+ : "a"(nr), "b"(a0), "c"(a1), "d"(a2), "S"(a3));
+
return r;
}
@@ -1314,8 +1321,10 @@ bool vm_is_unrestricted_guest(struct kvm_vm *vm)
void kvm_arch_main(void)
{
+ is_cpu_amd = cpu_vendor_string_is("AuthenticAMD") ? 1 : 0;
}
void kvm_arch_post_vm_load(struct kvm_vm *vm)
{
+ sync_global_to_guest(vm, is_cpu_amd);
}
--
2.37.2.789.g6183377224-goog
