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b=p4P+0ktiJe+KqobJTjuo+NuiWkUSCFq8R2deK3blc1nY6Loh6OUX3CufQceCTuS74L kukOP9Jut8yAqL/qkGNoV/SLaK3SakVy3Dw5rqZa/ZfglN/QjxdrwseytBuGPI5alu23 rKlSWl6x2zWC7CWJZ6MhKu2gc9q4nSYJVGFg2ppQtEmvQyT35X1qsYFX2zrFkiHjxOJe PYWh9lsnjMk48n9A+SQjmo5NMVqrHAiiS7o9BcUkYNW6EwTAm2IpKSpUqkX+KWAguVdw rlS4aI357RhrUTvuUtTS4ZnPeTOVPEV5LCptF/uTlSZi2Oi0PqD1oZjKQublCv9BkGkq G05g== X-Gm-Message-State: AOJu0YzuK5CWKIWLmHmZ1uV2NurTHlMPFLyNS7s47IljVXVYIt0X5k2A Zq5ci03MhIkjOcgubzeSxBqWscv7EtgFBhE6OYUt0Gtr8lomr2MlkoFljcPuiWenm7XVrKPRvnM NXQ== X-Google-Smtp-Source: AGHT+IFqzRS1xOg2oJDncuDOdOtR7gITdwbfvBFuJ4xWEWgDQEplutdiZUKmbH0mIVak18Oaak6LM032atM= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:9d:3983:ac13:c240]) (user=seanjc job=sendgmr) by 2002:a25:b205:0:b0:e25:17cb:352e with SMTP id 3f1490d57ef6-e28fe43f3f5mr4095276.9.1728584753336; Thu, 10 Oct 2024 11:25:53 -0700 (PDT) Reply-To: Sean Christopherson Date: Thu, 10 Oct 2024 11:23:31 -0700 In-Reply-To: <20241010182427.1434605-1-seanjc@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241010182427.1434605-1-seanjc@google.com> X-Mailer: git-send-email 2.47.0.rc1.288.g06298d1525-goog Message-ID: <20241010182427.1434605-30-seanjc@google.com> Subject: [PATCH v13 29/85] KVM: pfncache: Precisely track refcounted pages From: Sean Christopherson To: Paolo Bonzini , Marc Zyngier , Oliver Upton , Tianrui Zhao , Bibo Mao , Huacai Chen , Michael Ellerman , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Sean Christopherson Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, " =?utf-8?q?Alex_Benn=C3=A9e?= " , Yan Zhao , David Matlack , David Stevens , Andrew Jones Track refcounted struct page memory using kvm_follow_pfn.refcounted_page instead of relying on kvm_release_pfn_clean() to correctly detect that the pfn is associated with a struct page. Tested-by: Alex Bennée Signed-off-by: Sean Christopherson --- virt/kvm/pfncache.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c index 067daf9ad6ef..728d2c1b488a 100644 --- a/virt/kvm/pfncache.c +++ b/virt/kvm/pfncache.c @@ -159,11 +159,14 @@ static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc) kvm_pfn_t new_pfn = KVM_PFN_ERR_FAULT; void *new_khva = NULL; unsigned long mmu_seq; + struct page *page; + struct kvm_follow_pfn kfp = { .slot = gpc->memslot, .gfn = gpa_to_gfn(gpc->gpa), .flags = FOLL_WRITE, .hva = gpc->uhva, + .refcounted_page = &page, }; lockdep_assert_held(&gpc->refresh_lock); @@ -198,7 +201,7 @@ static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc) if (new_khva != old_khva) gpc_unmap(new_pfn, new_khva); - kvm_release_pfn_clean(new_pfn); + kvm_release_page_unused(page); cond_resched(); } @@ -218,7 +221,7 @@ static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc) new_khva = gpc_map(new_pfn); if (!new_khva) { - kvm_release_pfn_clean(new_pfn); + kvm_release_page_unused(page); goto out_error; } @@ -236,11 +239,11 @@ static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc) gpc->khva = new_khva + offset_in_page(gpc->uhva); /* - * Put the reference to the _new_ pfn. The pfn is now tracked by the + * Put the reference to the _new_ page. The page is now tracked by the * cache and can be safely migrated, swapped, etc... as the cache will * invalidate any mappings in response to relevant mmu_notifier events. */ - kvm_release_pfn_clean(new_pfn); + kvm_release_page_clean(page); return 0;