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Fri, 06 Mar 2026 06:02:47 -0800 (PST) Date: Fri, 6 Mar 2026 14:02:30 +0000 In-Reply-To: <20260306140232.2193802-1-tabba@google.com> Mime-Version: 1.0 References: <20260306140232.2193802-1-tabba@google.com> X-Mailer: git-send-email 2.53.0.473.g4a7958ca14-goog Message-ID: <20260306140232.2193802-12-tabba@google.com> Subject: [PATCH v1 11/13] KVM: arm64: Optimize early exit checks in kvm_s2_fault_pin_pfn() From: Fuad Tabba To: kvm@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, qperret@google.com, vdonnefort@google.com, tabba@google.com Content-Type: text/plain; charset="UTF-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260306_060250_100246_0782FEE0 X-CRM114-Status: GOOD ( 11.35 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Optimize the early exit checks in kvm_s2_fault_pin_pfn by grouping all error responses under the generic is_error_noslot_pfn check first, avoiding unnecessary branches in the hot path. Signed-off-by: Fuad Tabba --- arch/arm64/kvm/mmu.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 2d6e749c1756..9265a7fc43f7 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1791,12 +1791,13 @@ static int kvm_s2_fault_pin_pfn(struct kvm_s2_fault *fault) fault->pfn = __kvm_faultin_pfn(fault->memslot, fault->gfn, fault->write_fault ? FOLL_WRITE : 0, &fault->writable, &fault->page); - if (fault->pfn == KVM_PFN_ERR_HWPOISON) { - kvm_send_hwpoison_signal(fault->hva, __ffs(fault->vma_pagesize)); - return 0; - } - if (is_error_noslot_pfn(fault->pfn)) + if (unlikely(is_error_noslot_pfn(fault->pfn))) { + if (fault->pfn == KVM_PFN_ERR_HWPOISON) { + kvm_send_hwpoison_signal(fault->hva, __ffs(fault->vma_pagesize)); + return 0; + } return -EFAULT; + } return 1; } -- 2.53.0.473.g4a7958ca14-goog