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Date: Thu, 20 Jan 2022 19:48:21 +0800
From: Like Xu <like.xu.linux@...il.com>
To: Paolo Bonzini <pbonzini@...hat.com>
Cc: Sean Christopherson <seanjc@...gle.com>,
Jim Mattson <jmattson@...gle.com>,
Wanpeng Li <wanpengli@...cent.com>,
Vitaly Kuznetsov <vkuznets@...hat.com>,
Joerg Roedel <joro@...tes.org>, x86@...nel.org,
kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2] selftests: kvm/x86: Check if cpuid_d_0_ebx follows XCR0
value change
From: Like Xu <likexu@...cent.com>
Intel SDM says the CPUID.0xd.EBX reports the maximum size required by
enabled features in XCR0. Add a simple test that writes two different
non #GP values via __xsetbv() and verify that the cpuid data is updated.
The oddity thing is that CPUID[0d, 00].ebx doesn't enumerate the
XFEATURE_SSE size if only set bits 0 and 1:
XCR0 = 001B, ebx=00000240
XCR0 = 011B, ebx=00000240
XCR0 = 111B, ebx=00000340
Opportunistically, move the __x{s,g}etbv helpers to the x86_64/processor.h
Signed-off-by: Like Xu <likexu@...cent.com>
---
.../selftests/kvm/include/x86_64/processor.h | 18 +++++++++
tools/testing/selftests/kvm/x86_64/amx_test.c | 18 ---------
.../testing/selftests/kvm/x86_64/cpuid_test.c | 40 +++++++++++++++++--
3 files changed, 55 insertions(+), 21 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h
b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 122447827954..65097ca6d7b2 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -296,6 +296,24 @@ static inline void cpuid(uint32_t *eax, uint32_t *ebx,
: "memory");
}
+static inline u64 __xgetbv(u32 index)
+{
+ u32 eax, edx;
+
+ asm volatile("xgetbv;"
+ : "=a" (eax), "=d" (edx)
+ : "c" (index));
+ return eax + ((u64)edx << 32);
+}
+
+static inline void __xsetbv(u32 index, u64 value)
+{
+ u32 eax = value;
+ u32 edx = value >> 32;
+
+ asm volatile("xsetbv" :: "a" (eax), "d" (edx), "c" (index));
+}
+
#define SET_XMM(__var, __xmm) \
asm volatile("movq %0, %%"#__xmm : : "r"(__var) : #__xmm)
diff --git a/tools/testing/selftests/kvm/x86_64/amx_test.c
b/tools/testing/selftests/kvm/x86_64/amx_test.c
index 523c1e99ed64..c3cbb2dc450d 100644
--- a/tools/testing/selftests/kvm/x86_64/amx_test.c
+++ b/tools/testing/selftests/kvm/x86_64/amx_test.c
@@ -78,24 +78,6 @@ struct xtile_info {
static struct xtile_info xtile;
-static inline u64 __xgetbv(u32 index)
-{
- u32 eax, edx;
-
- asm volatile("xgetbv;"
- : "=a" (eax), "=d" (edx)
- : "c" (index));
- return eax + ((u64)edx << 32);
-}
-
-static inline void __xsetbv(u32 index, u64 value)
-{
- u32 eax = value;
- u32 edx = value >> 32;
-
- asm volatile("xsetbv" :: "a" (eax), "d" (edx), "c" (index));
-}
-
static inline void __ldtilecfg(void *cfg)
{
asm volatile(".byte 0xc4,0xe2,0x78,0x49,0x00"
diff --git a/tools/testing/selftests/kvm/x86_64/cpuid_test.c
b/tools/testing/selftests/kvm/x86_64/cpuid_test.c
index 16d2465c5634..6f280a12b849 100644
--- a/tools/testing/selftests/kvm/x86_64/cpuid_test.c
+++ b/tools/testing/selftests/kvm/x86_64/cpuid_test.c
@@ -20,8 +20,7 @@ struct {
u32 index;
} mangled_cpuids[] = {
/*
- * These entries depend on the vCPU's XCR0 register and IA32_XSS MSR,
- * which are not controlled for by this test.
+ * These entries depend on the vCPU's XCR0 register and IA32_XSS MSR.
*/
{.function = 0xd, .index = 0},
{.function = 0xd, .index = 1},
@@ -55,6 +54,37 @@ static void test_cpuid_40000000(struct kvm_cpuid2 *guest_cpuid)
GUEST_ASSERT(eax == 0x40000001);
}
+static void test_cpuid_d(struct kvm_cpuid2 *guest_cpuid)
+{
+ uint64_t cr4;
+ u32 eax, ebx, ecx, edx;
+ u32 size001, size011, size111;
+
+ cr4 = get_cr4();
+ cr4 |= X86_CR4_OSXSAVE;
+ set_cr4(cr4);
+
+ __xsetbv(0x0, 0x1);
+ eax = 0xd;
+ ebx = ecx = edx = 0;
+ cpuid(&eax, &ebx, &ecx, &edx);
+ size001 = ebx;
+
+ __xsetbv(0x0, 0x7);
+ eax = 0xd;
+ ebx = ecx = edx = 0;
+ cpuid(&eax, &ebx, &ecx, &edx);
+ size111 = ebx;
+
+ __xsetbv(0x0, 0x3);
+ eax = 0xd;
+ ebx = ecx = edx = 0;
+ cpuid(&eax, &ebx, &ecx, &edx);
+ size011 = ebx;
+
+ GUEST_ASSERT(size001 == size011 && size011 != size111);
+}
+
static void guest_main(struct kvm_cpuid2 *guest_cpuid)
{
GUEST_SYNC(1);
@@ -65,6 +95,10 @@ static void guest_main(struct kvm_cpuid2 *guest_cpuid)
test_cpuid_40000000(guest_cpuid);
+ GUEST_SYNC(3);
+
+ test_cpuid_d(guest_cpuid);
+
GUEST_DONE();
}
@@ -200,7 +234,7 @@ int main(void)
vcpu_args_set(vm, VCPU_ID, 1, cpuid_gva);
- for (stage = 0; stage < 3; stage++)
+ for (stage = 0; stage < 4; stage++)
run_vcpu(vm, VCPU_ID, stage);
set_cpuid_after_run(vm, cpuid2);
--
2.33.1
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