linux-kernel - [RFC PATCH v4 3/8] KVM:CPUID: Fix xsaves area size calculation for CPUID.(EAX=0xD,ECX=1).

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Date:   Mon, 18 Mar 2019 23:03:46 +0800
From:   Yang Weijiang <weijiang.yang@...el.com>
To:     pbonzini@...hat.com, kvm@...r.kernel.org, mst@...hat.com,
        rkrcmar@...hat.com, jmattson@...gle.com,
        linux-kernel@...r.kernel.org, yu-cheng.yu@...el.com
Cc:     Yang Weijiang <weijiang.yang@...el.com>,
        Zhang Yi Z <yi.z.zhang@...ux.intel.com>
Subject: [RFC PATCH v4 3/8] KVM:CPUID: Fix xsaves area size calculation for CPUID.(EAX=0xD,ECX=1).

According to latest Software Development Manual vol.2/3.2,
for CPUID.(EAX=0xD,ECX=1), it should report xsaves area size
containing all states enabled  by XCR0|IA32_MSR_XSS.

Signed-off-by: Zhang Yi Z <yi.z.zhang@...ux.intel.com>
Signed-off-by: Yang Weijiang <weijiang.yang@...el.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 53abd6019c68..29d6a5cdc746 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -126,7 +126,8 @@ 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
-- 
2.17.1