linux-kernel - [PATCH v2 24/32] KVM: SVM: Drop explicit check on MSRPM offset when emulating SEV-ES accesses

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250610225737.156318-25-seanjc@google.com>
Date: Tue, 10 Jun 2025 15:57:29 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Chao Gao <chao.gao@...el.com>, Borislav Petkov <bp@...en8.de>, Xin Li <xin@...or.com>, 
	Dapeng Mi <dapeng1.mi@...ux.intel.com>, Francesco Lavra <francescolavra.fl@...il.com>, 
	Manali Shukla <Manali.Shukla@....com>
Subject: [PATCH v2 24/32] KVM: SVM: Drop explicit check on MSRPM offset when
 emulating SEV-ES accesses

Now that msr_write_intercepted() defaults to true, i.e. accurately reflects
hardware behavior for out-of-range MSRs, and doesn't WARN (or BUG) on an
out-of-range MSR, drop sev_es_prevent_msr_access()'s svm_msrpm_offset()
check that guarded against calling msr_write_intercepted() with a "bad"
index.

Opportunistically clean up the helper's formatting.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/svm/svm.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 59088f68c557..9e4d08dba5f8 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2767,12 +2767,11 @@ static int svm_get_feature_msr(u32 msr, u64 *data)
 	return 0;
 }
 
-static bool
-sev_es_prevent_msr_access(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
+static bool sev_es_prevent_msr_access(struct kvm_vcpu *vcpu,
+				      struct msr_data *msr_info)
 {
 	return sev_es_guest(vcpu->kvm) &&
 	       vcpu->arch.guest_state_protected &&
-	       svm_msrpm_offset(msr_info->index) != MSR_INVALID &&
 	       !msr_write_intercepted(vcpu, msr_info->index);
 }
 
-- 
2.50.0.rc0.642.g800a2b2222-goog