From: Sean Christopherson <seanjc@google.com>
To: Yosry Ahmed <yosry.ahmed@linux.dev>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Jim Mattson <jmattson@google.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
stable@vger.kernel, Matteo Rizzo <matteorizzo@google.com>
Subject: Re: [PATCH 2/3] KVM: nSVM: Propagate SVM_EXIT_CR0_SEL_WRITE correctly for LMSW emulation
Date: Wed, 5 Nov 2025 11:44:27 -0800 [thread overview]
Message-ID: <aQupG93pUl-IYx8G@google.com> (raw)
In-Reply-To: <20251024192918.3191141-3-yosry.ahmed@linux.dev>
On Fri, Oct 24, 2025, Yosry Ahmed wrote:
> When emulating L2 instructions, svm_check_intercept() checks whether a
> write to CR0 should trigger a synthesized #VMEXIT with
> SVM_EXIT_CR0_SEL_WRITE. For MOV-to-CR0, SVM_EXIT_CR0_SEL_WRITE is only
> triggered if any bit other than CR0.MP and CR0.TS is updated. However,
> according to the APM (24593—Rev. 3.42—March 2024, Table 15-7):
>
> The LMSW instruction treats the selective CR0-write
> intercept as a non-selective intercept (i.e., it intercepts
> regardless of the value being written).
>
> Skip checking the changed bits for x86_intercept_lmsw and always inject
> SVM_EXIT_CR0_SEL_WRITE.
>
> Fixes: cfec82cb7d31 ("KVM: SVM: Add intercept check for emulated cr accesses")
> Cc: stable@vger.kernel
Bad email (mostly in case you're using a macro for this; the next patch has the
same typo).
next prev parent reply other threads:[~2025-11-05 19:44 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-24 19:29 [PATCH 0/3] KVM: nSVM: Fixes for SVM_EXIT_CR0_SEL_WRITE injection Yosry Ahmed
2025-10-24 19:29 ` [PATCH 1/3] KVM: nSVM: Remove redundant cases in nested_svm_intercept() Yosry Ahmed
2025-10-24 19:29 ` [PATCH 2/3] KVM: nSVM: Propagate SVM_EXIT_CR0_SEL_WRITE correctly for LMSW emulation Yosry Ahmed
2025-11-05 19:44 ` Sean Christopherson [this message]
2025-11-05 19:59 ` Yosry Ahmed
2025-10-24 19:29 ` [PATCH 3/3] KVM: nSVM: Avoid incorrect injection of SVM_EXIT_CR0_SEL_WRITE Yosry Ahmed
2025-11-05 19:48 ` Sean Christopherson
2025-11-05 20:04 ` Yosry Ahmed
2025-11-05 20:37 ` Sean Christopherson
2025-11-05 21:35 ` Yosry Ahmed
2025-10-24 19:51 ` [PATCH 0/3] KVM: nSVM: Fixes for SVM_EXIT_CR0_SEL_WRITE injection Yosry Ahmed
2025-11-10 15:37 ` Sean Christopherson
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