From nobody Mon Feb 9 11:05:01 2026 Received: from mail-pf1-f201.google.com (mail-pf1-f201.google.com [209.85.210.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 73FF91E376B for ; Thu, 21 Nov 2024 18:53:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732215238; cv=none; b=EznAYELWdIlAvifY19jAdGBAUL2PN3VCiIXAywXjjaLhDJohYgKemrwFOIyMhz+HEk0RQRVp/m+9IXasiW0XaDjRBAf8OfO5HBC61DSPNCQ9DEYA+cmW7CVeto3SNt5Q0gUeNtEAFpQNz84xNcjjKLCuFfbjl+gFbJK+fIeQUPI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732215238; c=relaxed/simple; bh=80AJRXxgHUR06s0FkZz93urmoI/O6TPv0yGQJeLF4Ws=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Cm0oC/Lalk1LkKvZ7DeLQRzpV2gdTKNyGOdRuNCaS89FIBNzRtGRdUIMl5Xgl4NXzse2e0YI+MfNEuLpfWEzReSW1gQ6Jf8o9gw2Vu7NAI7KaoDm1CXmRxgWvZi73z60jtoxWJQgB88XKNwQ116DHFtzyyM90PFb/OqUrq/2fV0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--mizhang.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=pqMKSLaW; arc=none smtp.client-ip=209.85.210.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--mizhang.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="pqMKSLaW" Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-722531f7806so1681135b3a.0 for ; Thu, 21 Nov 2024 10:53:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1732215234; x=1732820034; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=u7lzN3ovy8rt3qRKTNWPH3t6jAPHyPUfK7VhgkoNSLI=; b=pqMKSLaWv0Tsh7Nk1K4KFSSgLnBMVq5RMs38Tx+Wdr3KCVykc0Pfj1PCwvTAP7dtR/ SZnPufL+Oa1SjX3IhI6iqJp2KQry44tsmllHW3AzhOfXkrGgSuAtvbmK/eXqlxBpU+7+ PDHjDPfAAMvMyVWJMR2cxcfD5n/0tSOHpeod6O/kRWIdBIVpjl06Ij/XOuX5fojrcUu0 r8dSZqFWO7mmQ1o+FMWdh7fVJ4XRJMwWV4WA3MD6wCwCyi1rMmqhFy+/CSUJFqW3PueQ LJCDPH5wksS80BBCWO1/KhSKmfLS6/WFGwWv9YDXjfso26mI8EqTX6/sYzhNMLrMkYbW UG1w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1732215234; x=1732820034; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=u7lzN3ovy8rt3qRKTNWPH3t6jAPHyPUfK7VhgkoNSLI=; b=K+bn3MkXNmb4+cAn7FynB4yNwUiElqBAt0CWMfLZoGV7hCMwa3xtTsWa6YKoC/xIsk 2LxH/C4zubZQ8orvtb5lUUJN4lQ4xq43/aJMe3il+to9UmR4XfTKYmLdddPJHAXu53X9 ytztFiGXj0ugkVU4K7d35WIDn1SnzpvXaOau7JoIOm5NQy1hewLSuO0WEHNahQO+uHMZ V7O5DtuKYUh62SmvzgbpC4Vj84GQmkfQ6JdPQjwl3p8vOwtWwyjFvEriy6CBjEwG+Cb+ 2Q1LGfYdWkLeAtIu0NQ8Uk576HzIGMmhlSct8RWpqBpjIRBjCow6K5qWji6MrU0Obl/Y S6Kg== X-Forwarded-Encrypted: i=1; AJvYcCVQT9YQfps3DufE1gRs1huc8PGWOf1nntSzRjgtwnf0fxZIwp3Z6NxRgsDx7YLYt99mHJPPY9nRfTCCylc=@vger.kernel.org X-Gm-Message-State: AOJu0YxAMwEamrOairB+8adrzVOqcx/kn7GV4kPySOCQ0IIRkbKiXIBr 8fpiOJ2Jv33RiNB86HDNVgrML7GP38Kt/Fs9jGudTEPsJ2IIhhYQNNJg/ZIClcuL/UfEgcHTgkK UHhE9qA== X-Google-Smtp-Source: AGHT+IE0CLSo7knZFzWKfqBspTMKtJgzSjy6POJ7md/JMhCXlD1vM+E4fOblN3WVaGm9ltr3SlK9z7I68mrO X-Received: from mizhang-super.c.googlers.com ([34.105.13.176]) (user=mizhang job=sendgmr) by 2002:a62:e811:0:b0:724:daf0:e060 with SMTP id d2e1a72fcca58-724df3c0f18mr43b3a.1.1732215233908; Thu, 21 Nov 2024 10:53:53 -0800 (PST) Reply-To: Mingwei Zhang Date: Thu, 21 Nov 2024 18:53:13 +0000 In-Reply-To: <20241121185315.3416855-1-mizhang@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241121185315.3416855-1-mizhang@google.com> X-Mailer: git-send-email 2.47.0.371.ga323438b13-goog Message-ID: <20241121185315.3416855-22-mizhang@google.com> Subject: [RFC PATCH 21/22] KVM: SVM: Pass through guest reads of IA32_[AM]PERF From: Mingwei Zhang To: Sean Christopherson , Paolo Bonzini , Huang Rui , "Gautham R. Shenoy" , Mario Limonciello , "Rafael J. Wysocki" , Viresh Kumar , Srinivas Pandruvada , Len Brown Cc: "H. Peter Anvin" , Perry Yuan , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Jim Mattson , Mingwei Zhang Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Allow direct guest rdmsr access to IA32_APERF and IA32_MPERF while continuing to intercept guest wrmsr. Direct read access reduces overhead for guests that poll these MSRs frequently (e.g. every scheduler tick), while write interception remains necessary to maintain proper host offset tracking. Signed-off-by: Mingwei Zhang Co-developed-by: Jim Mattson Signed-off-by: Jim Mattson --- arch/x86/kvm/svm/svm.c | 7 +++++++ arch/x86/kvm/svm/svm.h | 2 +- 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 9df3e1e5ae81a..332947e0e9670 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -142,6 +142,8 @@ static const struct svm_direct_access_msrs { { .index =3D X2APIC_MSR(APIC_TMICT), .always =3D false }, { .index =3D X2APIC_MSR(APIC_TMCCT), .always =3D false }, { .index =3D X2APIC_MSR(APIC_TDCR), .always =3D false }, + { .index =3D MSR_IA32_APERF, .always =3D false }, + { .index =3D MSR_IA32_MPERF, .always =3D false }, { .index =3D MSR_INVALID, .always =3D false }, }; =20 @@ -1231,6 +1233,11 @@ static inline void init_vmcb_after_set_cpuid(struct = kvm_vcpu *vcpu) set_msr_interception(vcpu, svm->msrpm, MSR_IA32_SYSENTER_EIP, 1, 1); set_msr_interception(vcpu, svm->msrpm, MSR_IA32_SYSENTER_ESP, 1, 1); } + + set_msr_interception(vcpu, svm->msrpm, MSR_IA32_APERF, + guest_can_use(vcpu, X86_FEATURE_APERFMPERF), 0); + set_msr_interception(vcpu, svm->msrpm, MSR_IA32_MPERF, + guest_can_use(vcpu, X86_FEATURE_APERFMPERF), 0); } =20 static void init_vmcb(struct kvm_vcpu *vcpu) diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 43fa6a16eb191..5ae5a13b9771a 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -44,7 +44,7 @@ static inline struct page *__sme_pa_to_page(unsigned long= pa) #define IOPM_SIZE PAGE_SIZE * 3 #define MSRPM_SIZE PAGE_SIZE * 2 =20 -#define MAX_DIRECT_ACCESS_MSRS 48 +#define MAX_DIRECT_ACCESS_MSRS 50 #define MSRPM_OFFSETS 32 extern u32 msrpm_offsets[MSRPM_OFFSETS] __read_mostly; extern bool npt_enabled; --=20 2.47.0.371.ga323438b13-goog