From: Nathan Chancellor <nathan@kernel.org>
To: Michael Roth <michael.roth@amd.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Paolo Bonzini <pbonzini@redhat.com>,
linux-coco@lists.linux.dev,
Sean Christopherson <seanjc@google.com>
Subject: Re: [PATCH] KVM: SEV: Fix uninitialized firmware error code
Date: Wed, 15 May 2024 15:02:25 -0700 [thread overview]
Message-ID: <20240515220225.GA2014948@thelio-3990X> (raw)
In-Reply-To: <20240513172704.718533-1-michael.roth@amd.com>
On Mon, May 13, 2024 at 12:27:04PM -0500, Michael Roth wrote:
> The current code triggers a clang warning due to passing back an
> uninitialized firmware return code in cases where an attestation request
> is aborted before getting sent to userspace. Since firmware has not been
> involved at this point the appropriate value is 0.
>
> Reported-by: Nathan Chancellor <nathan@kernel.org>
> Closes: https://lore.kernel.org/kvm/20240513151920.GA3061950@thelio-3990X/
> Fixes: 32fde9e18b3f ("KVM: SEV: Provide support for SNP_EXTENDED_GUEST_REQUEST NAE event")
> Signed-off-by: Michael Roth <michael.roth@amd.com>
This obviously resolves the warning:
Tested-by: Nathan Chancellor <nathan@kernel.org> # build
> ---
> arch/x86/kvm/svm/sev.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index 57c2c8025547..59c0d89a4d52 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -4048,7 +4048,6 @@ static int snp_begin_ext_guest_req(struct kvm_vcpu *vcpu)
> int vmm_ret = SNP_GUEST_VMM_ERR_GENERIC;
> struct vcpu_svm *svm = to_svm(vcpu);
> unsigned long data_npages;
> - sev_ret_code fw_err;
> gpa_t data_gpa;
>
> if (!sev_snp_guest(vcpu->kvm))
> @@ -4075,7 +4074,7 @@ static int snp_begin_ext_guest_req(struct kvm_vcpu *vcpu)
> return 0; /* forward request to userspace */
>
> abort_request:
> - ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, SNP_GUEST_ERR(vmm_ret, fw_err));
> + ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, SNP_GUEST_ERR(vmm_ret, 0));
> return 1; /* resume guest */
> }
>
> --
> 2.25.1
>
prev parent reply other threads:[~2024-05-15 22:02 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-13 17:27 [PATCH] KVM: SEV: Fix uninitialized firmware error code Michael Roth
2024-05-15 22:02 ` Nathan Chancellor [this message]
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