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From: Yang Weijiang <weijiang.yang@intel.com>
To: pbonzini@redhat.com, seanjc@google.com, vkuznets@redhat.com,
	jmattson@google.com, wei.w.wang@intel.com,
	like.xu.linux@gmail.com, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: Like Xu <like.xu@linux.intel.com>,
	Yang Weijiang <weijiang.yang@intel.com>
Subject: [PATCH v5 11/13] KVM: x86: Add XSAVE Support for Architectural LBR
Date: Fri,  9 Jul 2021 18:05:09 +0800	[thread overview]
Message-ID: <1625825111-6604-12-git-send-email-weijiang.yang@intel.com> (raw)
In-Reply-To: <1625825111-6604-1-git-send-email-weijiang.yang@intel.com>

From: Like Xu <like.xu@linux.intel.com>

On processors supporting XSAVES and XRSTORS, Architectural LBR XSAVE
support is enumerated from CPUID.(EAX=0DH, ECX=1):ECX[bit 15].
The detailed sub-leaf for Arch LBR is enumerated in CPUID.(0DH, 0FH).

XSAVES provides a faster means than RDMSR for guest to read all LBRs.
When guest IA32_XSS[bit 15] is set, the Arch LBR state can be saved using
XSAVES and restored by XRSTORS with the appropriate RFBM.

Signed-off-by: Like Xu <like.xu@linux.intel.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 4 ++++
 arch/x86/kvm/x86.c     | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 636c50b95038..3eccda710495 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7337,6 +7337,10 @@ static __init void vmx_set_cpu_caps(void)
 		kvm_cpu_cap_clear(X86_FEATURE_INVPCID);
 	if (vmx_pt_mode_is_host_guest())
 		kvm_cpu_cap_check_and_set(X86_FEATURE_INTEL_PT);
+	if (!cpu_has_vmx_arch_lbr()) {
+		kvm_cpu_cap_clear(X86_FEATURE_ARCH_LBR);
+		supported_xss &= ~XFEATURE_MASK_LBR;
+	}
 
 	if (!enable_sgx) {
 		kvm_cpu_cap_clear(X86_FEATURE_SGX);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2424d475a4d7..c09522c1f3ec 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -203,7 +203,7 @@ static struct kvm_user_return_msrs __percpu *user_return_msrs;
 				| XFEATURE_MASK_BNDCSR | XFEATURE_MASK_AVX512 \
 				| XFEATURE_MASK_PKRU)
 
-#define KVM_SUPPORTED_XSS     0
+#define KVM_SUPPORTED_XSS     XFEATURE_MASK_LBR
 
 u64 __read_mostly host_efer;
 EXPORT_SYMBOL_GPL(host_efer);
-- 
2.21.1


  parent reply	other threads:[~2021-07-09  9:51 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-09 10:04 [PATCH v5 00/13] Introduce Architectural LBR for vPMU Yang Weijiang
2021-07-09 10:04 ` [PATCH v5 01/13] perf/x86/intel: Fix the comment about guest LBR support on KVM Yang Weijiang
2021-07-09 10:05 ` [PATCH v5 02/13] perf/x86/lbr: Simplify the exposure check for the LBR_INFO registers Yang Weijiang
2021-07-09 10:05 ` [PATCH v5 03/13] KVM: x86: Add arch LBR MSRs to msrs_to_save_all list Yang Weijiang
2021-07-09 18:24   ` Jim Mattson
2021-07-12  8:55     ` Yang Weijiang
2021-07-09 10:05 ` [PATCH v5 04/13] KVM: vmx/pmu: Emulate MSR_ARCH_LBR_DEPTH for guest Arch LBR Yang Weijiang
2021-07-09 20:35   ` Jim Mattson
2021-07-12  9:17     ` Yang Weijiang
2021-07-09 10:05 ` [PATCH v5 05/13] KVM: vmx/pmu: Emulate MSR_ARCH_LBR_CTL " Yang Weijiang
2021-07-09 21:55   ` Jim Mattson
2021-07-12  9:36     ` Yang Weijiang
2021-07-12 10:10       ` Like Xu
2021-07-13  9:05         ` Yang Weijiang
2021-07-10  0:42   ` kernel test robot
2021-07-09 10:05 ` [PATCH v5 06/13] KVM: x86/vmx: Save/Restore host MSR_ARCH_LBR_CTL state Yang Weijiang
2021-07-09 22:54   ` Jim Mattson
2021-07-09 23:41     ` Jim Mattson
2021-07-12  9:53       ` Yang Weijiang
2021-07-12 10:19         ` Like Xu
2021-07-12 17:20           ` Jim Mattson
2021-07-12 17:45             ` Jim Mattson
2021-07-13  9:49               ` Like Xu
2021-07-13 17:00                 ` Jim Mattson
2021-07-14 13:33                   ` Like Xu
2021-07-14 16:15                     ` Jim Mattson
2021-07-13  9:53             ` Yang Weijiang
2021-07-12  9:50     ` Yang Weijiang
2021-07-12 17:23       ` Jim Mattson
2021-07-13  9:47         ` Yang Weijiang
2021-07-13 10:16           ` Like Xu
2021-07-13 17:12             ` Jim Mattson
2021-07-14 13:55               ` Like Xu
2021-07-09 10:05 ` [PATCH v5 07/13] KVM: x86/pmu: Refactor code to support guest Arch LBR Yang Weijiang
2021-07-09 10:05 ` [PATCH v5 08/13] KVM: x86: Refresh CPUID on writes to MSR_IA32_XSS Yang Weijiang
2021-07-09 10:05 ` [PATCH v5 09/13] KVM: x86: Report XSS as an MSR to be saved if there are supported features Yang Weijiang
2021-07-09 10:05 ` [PATCH v5 10/13] KVM: x86: Refine the matching and clearing logic for supported_xss Yang Weijiang
2021-07-09 10:05 ` Yang Weijiang [this message]
2021-07-09 10:05 ` [PATCH v5 12/13] KVM: x86/vmx: Check Arch LBR config when return perf capabilities Yang Weijiang
2021-07-09 10:05 ` [PATCH v5 13/13] KVM: x86/cpuid: Advise Arch LBR feature in CPUID Yang Weijiang

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