[PATCH v5 3/8] KVM: x86: Fix XSAVE size calculation issue

From: Yang Weijiang
Date: Wed May 22 2019 - 03:04:42 EST


According to the SDM, Vol 2, CPUID(EAX=0xD,ECX=1) reports the
XSAVE size containing all states enabled by XCR0|IA32_MSR_XSS.

Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx>
Co-developed-by: Zhang Yi Z <yi.z.zhang@xxxxxxxxxxxxxxx>
---
arch/x86/kvm/cpuid.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index b9fc967fe55a..7be16ef0ea4a 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -123,7 +123,8 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu)

best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
if (best && (best->eax & (F(XSAVES) | F(XSAVEC))))
- best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
+ best->ebx = xstate_required_size(vcpu->arch.xcr0 |
+ kvm_supported_xss(), true);

/*
* The existing code assumes virtual address is 48-bit or 57-bit in the
--
2.17.2