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From: Like Xu <like.xu@linux.intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	weijiang.yang@intel.com, wei.w.wang@intel.com,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [RESEND PATCH v4 09/10] KVM: x86: Refine the matching and clearing logic for supported_xss
Date: Mon, 10 May 2021 16:15:33 +0800	[thread overview]
Message-ID: <20210510081535.94184-10-like.xu@linux.intel.com> (raw)
In-Reply-To: <20210510081535.94184-1-like.xu@linux.intel.com>

Refine the code path of the existing clearing of supported_xss in this way:
initialize the supported_xss with the filter of KVM_SUPPORTED_XSS mask and
update its value in a bit clear manner (rather than bit setting).

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Like Xu <like.xu@linux.intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 5 +++--
 arch/x86/kvm/x86.c     | 6 +++++-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index f88c6e8f7a3a..d080bf163565 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7384,9 +7384,10 @@ static __init void vmx_set_cpu_caps(void)
 		kvm_cpu_cap_set(X86_FEATURE_UMIP);
 
 	/* CPUID 0xD.1 */
-	supported_xss = 0;
-	if (!cpu_has_vmx_xsaves())
+	if (!cpu_has_vmx_xsaves()) {
 		kvm_cpu_cap_clear(X86_FEATURE_XSAVES);
+		supported_xss = 0;
+	}
 
 	/* CPUID 0x80000001 and 0x7 (RDPID) */
 	if (!cpu_has_vmx_rdtscp()) {
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b699f7a37b1a..3a32bea2277e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -203,6 +203,8 @@ static struct kvm_user_return_msrs __percpu *user_return_msrs;
 				| XFEATURE_MASK_BNDCSR | XFEATURE_MASK_AVX512 \
 				| XFEATURE_MASK_PKRU)
 
+#define KVM_SUPPORTED_XSS     0
+
 u64 __read_mostly host_efer;
 EXPORT_SYMBOL_GPL(host_efer);
 
@@ -10619,8 +10621,10 @@ int kvm_arch_hardware_setup(void *opaque)
 
 	rdmsrl_safe(MSR_EFER, &host_efer);
 
-	if (boot_cpu_has(X86_FEATURE_XSAVES))
+	if (boot_cpu_has(X86_FEATURE_XSAVES)) {
 		rdmsrl(MSR_IA32_XSS, host_xss);
+		supported_xss = host_xss & KVM_SUPPORTED_XSS;
+	}
 
 	r = ops->hardware_setup();
 	if (r != 0)
-- 
2.31.1


  parent reply	other threads:[~2021-05-10  8:17 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-10  8:15 [RESEND PATCH v4 00/10] KVM: x86/pmu: Guest Architectural LBR Enabling Like Xu
2021-05-10  8:15 ` [RESEND PATCH v4 01/10] perf/x86/intel: Fix the comment about guest LBR support on KVM Like Xu
2021-05-10  8:15 ` [RESEND PATCH v4 02/10] perf/x86/lbr: Simplify the exposure check for the LBR_INFO registers Like Xu
2021-05-10  8:15 ` [RESEND PATCH v4 03/10] KVM: vmx/pmu: Add MSR_ARCH_LBR_DEPTH emulation for Arch LBR Like Xu
2021-06-23 18:03   ` Jim Mattson
2021-06-24  1:31     ` Yang Weijiang
2021-05-10  8:15 ` [RESEND PATCH v4 04/10] KVM: vmx/pmu: Add MSR_ARCH_LBR_CTL " Like Xu
2021-06-23 18:29   ` Jim Mattson
2021-06-24  1:35     ` Yang Weijiang
2021-05-10  8:15 ` [RESEND PATCH v4 05/10] KVM: vmx/pmu: Add Arch LBR emulation and its VMCS field Like Xu
2021-05-10  8:15 ` [RESEND PATCH v4 06/10] KVM: x86: Expose Architectural LBR CPUID leaf Like Xu
2021-05-10  8:15 ` [RESEND PATCH v4 07/10] KVM: x86: Refresh CPUID on writes to MSR_IA32_XSS Like Xu
2021-05-10  8:15 ` [RESEND PATCH v4 08/10] KVM: x86: Report XSS as an MSR to be saved if there are supported features Like Xu
2021-05-10  8:15 ` Like Xu [this message]
2021-05-10  8:15 ` [RESEND PATCH v4 10/10] KVM: x86: Add XSAVE Support for Architectural LBRs Like Xu
2021-05-10  8:15 ` [RESEND kvm-unit-tests PATCH v2] x86: Update guest LBR tests for Architectural LBR Like Xu
2021-06-22  9:01 ` [RESEND PATCH v4 00/10] KVM: x86/pmu: Guest Architectural LBR Enabling Yang Weijiang
2021-06-23 13:32   ` Like Xu

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