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

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Date:   Wed, 22 May 2019 15:00:56 +0800
From:   Yang Weijiang <weijiang.yang@...el.com>
To:     pbonzini@...hat.com, sean.j.christopherson@...el.com,
        mst@...hat.com, rkrcmar@...hat.com, jmattson@...gle.com,
        linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        yu-cheng.yu@...el.com
Cc:     weijiang.yang@...el.com
Subject: [PATCH v5 3/8] KVM: x86: Fix XSAVE size calculation issue

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@...el.com>
Co-developed-by: Zhang Yi Z <yi.z.zhang@...ux.intel.com>
---
 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