From: Tom Lendacky <thomas.lendacky@amd.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Borislav Petkov <bp@suse.de>,
Brijesh Singh <brijesh.singh@amd.com>
Subject: Re: [PATCH v3 02/13] KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails
Date: Fri, 22 Jan 2021 15:09:23 -0600 [thread overview]
Message-ID: <c013cd19-8120-838c-2357-f87a99f7ba1d@amd.com> (raw)
In-Reply-To: <20210122202144.2756381-3-seanjc@google.com>
On 1/22/21 2:21 PM, Sean Christopherson wrote:
> Free sev_asid_bitmap if the reclaim bitmap allocation fails, othwerise
> KVM will unnecessarily keep the bitmap when SEV is not fully enabled.
>
> Freeing the page is also necessary to avoid introducing a bug when a
> future patch eliminates svm_sev_enabled() in favor of using the global
> 'sev' flag directly. While sev_hardware_enabled() checks max_sev_asid,
> which is true even if KVM setup fails, 'sev' will be true if and only
> if KVM setup fully succeeds.
>
> Fixes: 33af3a7ef9e6 ("KVM: SVM: Reduce WBINVD/DF_FLUSH invocations")
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
> ---
> arch/x86/kvm/svm/sev.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index c8ffdbc81709..ec742dabbd5b 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -1274,8 +1274,11 @@ void __init sev_hardware_setup(void)
> goto out;
>
> sev_reclaim_asid_bitmap = bitmap_zalloc(max_sev_asid, GFP_KERNEL);
> - if (!sev_reclaim_asid_bitmap)
> + if (!sev_reclaim_asid_bitmap) {
> + bitmap_free(sev_asid_bitmap);
> + sev_asid_bitmap = NULL;
> goto out;
> + }
>
> pr_info("SEV supported: %u ASIDs\n", max_sev_asid - min_sev_asid + 1);
> sev_supported = true;
>
next prev parent reply other threads:[~2021-01-22 21:12 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-22 20:21 [PATCH v3 00/13] KVM: SVM: Misc SEV cleanups Sean Christopherson
2021-01-22 20:21 ` [PATCH v3 01/13] KVM: SVM: Zero out the VMCB array used to track SEV ASID association Sean Christopherson
2021-01-22 20:21 ` [PATCH v3 02/13] KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails Sean Christopherson
2021-01-22 21:09 ` Tom Lendacky [this message]
2021-01-22 20:21 ` [PATCH v3 03/13] KVM: SVM: Move SEV module params/variables to sev.c Sean Christopherson
2021-01-22 20:21 ` [PATCH v3 04/13] x86/sev: Drop redundant and potentially misleading 'sev_enabled' Sean Christopherson
2021-01-22 20:21 ` [PATCH v3 05/13] KVM: SVM: Append "_enabled" to module-scoped SEV/SEV-ES control variables Sean Christopherson
2021-01-22 20:21 ` [PATCH v3 06/13] KVM: SVM: Condition sev_enabled and sev_es_enabled on CONFIG_KVM_AMD_SEV=y Sean Christopherson
2021-01-22 20:21 ` [PATCH v3 07/13] KVM: SVM: Enable SEV/SEV-ES functionality by default (when supported) Sean Christopherson
2021-01-22 21:11 ` Tom Lendacky
2021-01-22 20:21 ` [PATCH v3 08/13] KVM: SVM: Unconditionally invoke sev_hardware_teardown() Sean Christopherson
2021-01-22 20:21 ` [PATCH v3 09/13] KVM: SVM: Explicitly check max SEV ASID during sev_hardware_setup() Sean Christopherson
2021-01-22 20:21 ` [PATCH v3 10/13] KVM: SVM: Move SEV VMCB tracking allocation to sev.c Sean Christopherson
2021-01-22 20:21 ` [PATCH v3 11/13] KVM: SVM: Drop redundant svm_sev_enabled() helper Sean Christopherson
2021-01-22 20:21 ` [PATCH v3 12/13] KVM: SVM: Remove an unnecessary prototype declaration of sev_flush_asids() Sean Christopherson
2021-01-22 20:21 ` [PATCH v3 13/13] KVM: SVM: Skip SEV cache flush if no ASIDs have been used Sean Christopherson
2021-01-22 21:16 ` Tom Lendacky
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