From: "Gupta, Pankaj" <pankaj.gupta@amd.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
"K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
Long Li <longli@microsoft.com>
Cc: kvm@vger.kernel.org, linux-hyperv@vger.kernel.org,
linux-kernel@vger.kernel.org, Jim Mattson <jmattson@google.com>,
Yosry Ahmed <yosry.ahmed@linux.dev>
Subject: Re: [PATCH v2 2/8] KVM: SVM: Open code handling of unexpected exits in svm_invoke_exit_handler()
Date: Fri, 2 Jan 2026 12:41:06 +0100 [thread overview]
Message-ID: <da6851da-979d-4c7a-9e19-08885f3ae042@amd.com> (raw)
In-Reply-To: <20251230211347.4099600-3-seanjc@google.com>
> Fold svm_check_exit_valid() and svm_handle_invalid_exit() into their sole
> caller, svm_invoke_exit_handler(), as having tiny single-use helpers makes
> the code unncessarily difficult to follow. This will also allow for
> additional cleanups in svm_invoke_exit_handler().
>
> No functional change intended.
>
> Suggested-by: Yosry Ahmed <yosry.ahmed@linux.dev>
> Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
> ---
> arch/x86/kvm/svm/svm.c | 25 ++++++++++---------------
> 1 file changed, 10 insertions(+), 15 deletions(-)
>
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index c2ddf2e0aa1a..a523011f0923 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -3443,23 +3443,13 @@ static void dump_vmcb(struct kvm_vcpu *vcpu)
> sev_free_decrypted_vmsa(vcpu, save);
> }
>
> -static bool svm_check_exit_valid(u64 exit_code)
> -{
> - return (exit_code < ARRAY_SIZE(svm_exit_handlers) &&
> - svm_exit_handlers[exit_code]);
> -}
> -
> -static int svm_handle_invalid_exit(struct kvm_vcpu *vcpu, u64 exit_code)
> -{
> - dump_vmcb(vcpu);
> - kvm_prepare_unexpected_reason_exit(vcpu, exit_code);
> - return 0;
> -}
> -
> int svm_invoke_exit_handler(struct kvm_vcpu *vcpu, u64 exit_code)
> {
> - if (!svm_check_exit_valid(exit_code))
> - return svm_handle_invalid_exit(vcpu, exit_code);
> + if (exit_code >= ARRAY_SIZE(svm_exit_handlers))
> + goto unexpected_vmexit;
> +
> + if (!svm_exit_handlers[exit_code])
> + goto unexpected_vmexit;
>
> #ifdef CONFIG_MITIGATION_RETPOLINE
> if (exit_code == SVM_EXIT_MSR)
> @@ -3478,6 +3468,11 @@ int svm_invoke_exit_handler(struct kvm_vcpu *vcpu, u64 exit_code)
> #endif
> #endif
> return svm_exit_handlers[exit_code](vcpu);
> +
> +unexpected_vmexit:
> + dump_vmcb(vcpu);
> + kvm_prepare_unexpected_reason_exit(vcpu, exit_code);
> + return 0;
> }
>
> static void svm_get_exit_info(struct kvm_vcpu *vcpu, u32 *reason,
next prev parent reply other threads:[~2026-01-02 11:41 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-30 21:13 [PATCH v2 0/8] KVM: SVM: Fix exit_code bugs Sean Christopherson
2025-12-30 21:13 ` [PATCH v2 1/8] KVM: SVM: Add a helper to detect VMRUN failures Sean Christopherson
2026-01-02 16:44 ` Yosry Ahmed
2025-12-30 21:13 ` [PATCH v2 2/8] KVM: SVM: Open code handling of unexpected exits in svm_invoke_exit_handler() Sean Christopherson
2026-01-02 11:41 ` Gupta, Pankaj [this message]
2025-12-30 21:13 ` [PATCH v2 3/8] KVM: SVM: Check for an unexpected VM-Exit after RETPOLINE "fast" handling Sean Christopherson
2025-12-30 21:13 ` [PATCH v2 4/8] KVM: SVM: Filter out 64-bit exit codes when invoking exit handlers on bare metal Sean Christopherson
2025-12-30 21:13 ` [PATCH v2 5/8] KVM: SVM: Treat exit_code as an unsigned 64-bit value through all of KVM Sean Christopherson
2025-12-30 21:13 ` [PATCH v2 6/8] KVM: SVM: Limit incorrect check on SVM_EXIT_ERR to running as a VM Sean Christopherson
2025-12-30 21:13 ` [PATCH v2 7/8] KVM: SVM: Harden exit_code against being used in Spectre-like attacks Sean Christopherson
2025-12-30 21:13 ` [PATCH v2 8/8] KVM: SVM: Assert that Hyper-V's HV_SVM_EXITCODE_ENL == SVM_EXIT_SW Sean Christopherson
2026-01-02 9:58 ` Vitaly Kuznetsov
2026-01-05 15:52 ` Sean Christopherson
2026-01-15 18:03 ` [PATCH v2 0/8] KVM: SVM: Fix exit_code bugs Sean Christopherson
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