From: Paolo Bonzini <pbonzini@redhat.com>
To: Sean Christopherson <seanjc@google.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>,
Tom Lendacky <thomas.lendacky@amd.com>,
Brijesh Singh <brijesh.singh@amd.com>
Subject: Re: [PATCH v2 14/14] KVM: SVM: Skip SEV cache flush if no ASIDs have been used
Date: Thu, 28 Jan 2021 16:10:24 +0100 [thread overview]
Message-ID: <55a63dfb-94a4-6ba2-31d1-c9b6830ff791@redhat.com> (raw)
In-Reply-To: <20210114003708.3798992-15-seanjc@google.com>
On 14/01/21 01:37, Sean Christopherson wrote:
> Skip SEV's expensive WBINVD and DF_FLUSH if there are no SEV ASIDs
> waiting to be reclaimed, e.g. if SEV was never used. This "fixes" an
> issue where the DF_FLUSH fails during hardware teardown if the original
> SEV_INIT failed. Ideally, SEV wouldn't be marked as enabled in KVM if
> SEV_INIT fails, but that's a problem for another day.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
> arch/x86/kvm/svm/sev.c | 22 ++++++++++------------
> 1 file changed, 10 insertions(+), 12 deletions(-)
>
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index 23a4bead4a82..e71bc742d8da 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -56,9 +56,14 @@ struct enc_region {
> unsigned long size;
> };
>
> -static int sev_flush_asids(void)
> +static int sev_flush_asids(int min_asid, int max_asid)
> {
> - int ret, error = 0;
> + int ret, pos, error = 0;
> +
> + /* Check if there are any ASIDs to reclaim before performing a flush */
> + pos = find_next_bit(sev_reclaim_asid_bitmap, max_sev_asid, min_asid);
> + if (pos >= max_asid)
> + return -EBUSY;
>
> /*
> * DEACTIVATE will clear the WBINVD indicator causing DF_FLUSH to fail,
> @@ -80,14 +85,7 @@ static int sev_flush_asids(void)
> /* Must be called with the sev_bitmap_lock held */
> static bool __sev_recycle_asids(int min_asid, int max_asid)
> {
> - int pos;
> -
> - /* Check if there are any ASIDs to reclaim before performing a flush */
> - pos = find_next_bit(sev_reclaim_asid_bitmap, max_sev_asid, min_asid);
> - if (pos >= max_asid)
> - return false;
> -
> - if (sev_flush_asids())
> + if (sev_flush_asids(min_asid, max_asid))
> return false;
>
> /* The flush process will flush all reclaimable SEV and SEV-ES ASIDs */
> @@ -1323,10 +1321,10 @@ void sev_hardware_teardown(void)
> if (!sev_enabled)
> return;
>
> + sev_flush_asids(0, max_sev_asid);
> +
> bitmap_free(sev_asid_bitmap);
> bitmap_free(sev_reclaim_asid_bitmap);
> -
> - sev_flush_asids();
> }
>
> int sev_cpu_init(struct svm_cpu_data *sd)
>
I can't find 00/14 in my inbox, so: queued 1-3 and 6-14, thanks.
Paolo
next prev parent reply other threads:[~2021-01-28 15:12 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-14 0:36 [PATCH v2 00/14] KVM: SVM: Misc SEV cleanups Sean Christopherson
2021-01-14 0:36 ` [PATCH v2 01/14] KVM: SVM: Zero out the VMCB array used to track SEV ASID association Sean Christopherson
2021-01-14 15:56 ` Tom Lendacky
2021-01-14 17:13 ` Sean Christopherson
2021-01-14 20:57 ` Brijesh Singh
2021-01-14 0:36 ` [PATCH v2 02/14] KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails Sean Christopherson
2021-01-14 15:49 ` Tom Lendacky
2021-01-14 17:12 ` Sean Christopherson
2021-01-14 18:02 ` Tom Lendacky
2021-01-14 19:17 ` Sean Christopherson
2021-01-14 0:36 ` [PATCH v2 03/14] KVM: SVM: Move SEV module params/variables to sev.c Sean Christopherson
2021-01-14 19:07 ` Tom Lendacky
2021-01-14 20:59 ` Brijesh Singh
2021-01-14 0:36 ` [PATCH v2 04/14] x86/cpufeatures: Assign dedicated feature word for AMD mem encryption Sean Christopherson
2021-01-14 11:35 ` Borislav Petkov
2021-01-14 17:09 ` Sean Christopherson
2021-01-14 17:16 ` Borislav Petkov
2021-01-28 15:09 ` Paolo Bonzini
2021-01-14 21:17 ` Brijesh Singh
2021-01-14 0:36 ` [PATCH v2 05/14] KVM: x86: Override reported SME/SEV feature flags with host mask Sean Christopherson
2021-01-14 21:18 ` Brijesh Singh
2021-01-28 15:07 ` Paolo Bonzini
2021-01-28 17:09 ` Sean Christopherson
2021-01-28 17:25 ` Paolo Bonzini
2021-01-14 0:37 ` [PATCH v2 06/14] x86/sev: Drop redundant and potentially misleading 'sev_enabled' Sean Christopherson
2021-01-14 17:54 ` Tom Lendacky
2021-01-14 21:24 ` Brijesh Singh
2021-01-14 0:37 ` [PATCH v2 07/14] KVM: SVM: Append "_enabled" to module-scoped SEV/SEV-ES control variables Sean Christopherson
2021-01-14 21:28 ` Brijesh Singh
2021-01-14 0:37 ` [PATCH v2 08/14] KVM: SVM: Condition sev_enabled and sev_es_enabled on CONFIG_KVM_AMD_SEV=y Sean Christopherson
2021-01-14 20:56 ` Tom Lendacky
2021-01-14 21:28 ` Brijesh Singh
2021-01-14 0:37 ` [PATCH v2 09/14] KVM: SVM: Unconditionally invoke sev_hardware_teardown() Sean Christopherson
2021-01-14 21:26 ` Tom Lendacky
2021-01-14 21:32 ` Brijesh Singh
2021-01-14 0:37 ` [PATCH v2 10/14] KVM: SVM: Explicitly check max SEV ASID during sev_hardware_setup() Sean Christopherson
2021-01-14 21:35 ` Brijesh Singh
2021-01-14 21:49 ` Tom Lendacky
2021-01-14 0:37 ` [PATCH v2 11/14] KVM: SVM: Move SEV VMCB tracking allocation to sev.c Sean Christopherson
2021-01-14 21:37 ` Brijesh Singh
2021-01-14 21:53 ` Tom Lendacky
2021-01-14 22:15 ` Tom Lendacky
2021-01-14 0:37 ` [PATCH v2 12/14] KVM: SVM: Drop redundant svm_sev_enabled() helper Sean Christopherson
2021-01-14 21:44 ` Brijesh Singh
2021-01-14 22:51 ` Tom Lendacky
2021-01-14 0:37 ` [PATCH v2 13/14] KVM: SVM: Remove an unnecessary prototype declaration of sev_flush_asids() Sean Christopherson
2021-01-14 21:45 ` Brijesh Singh
2021-01-14 22:53 ` Tom Lendacky
2021-01-14 0:37 ` [PATCH v2 14/14] KVM: SVM: Skip SEV cache flush if no ASIDs have been used Sean Christopherson
2021-01-15 15:07 ` Tom Lendacky
2021-01-15 17:19 ` Sean Christopherson
2021-01-28 15:10 ` Paolo Bonzini [this message]
2021-01-28 16:29 ` Sean Christopherson
2021-01-28 16:59 ` Paolo Bonzini
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