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AJvYcCXUZZKxy/yrwr4l8qLCgvQU23l3R/a1yVFGPycm4y18eGXYrhMgOM7+jKRmMCLIGozD3cBwrqFyAgt5Jhjd30+6@lists.infradead.org X-Gm-Message-State: AOJu0YzydlIFvzPoJWTbCFOgVHu/+9cxsLrT//fD7UykfD7rCh2z2HnC B9hJDykUBnHbh65kqdZegIfMhKv4s9AglVkFxILWCM9BSOfOEAY7L2+o9sWA09zDA3FMBPn2RXh BFQ== X-Google-Smtp-Source: AGHT+IG89v4lIFRhnNqxe9hFvIIxqDvldHGwH//6ib2L4odxYyk8SJA2JGOjXIHuxBeh8ylp7HgA6abaBbM= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:9d:3983:ac13:c240]) (user=seanjc job=sendgmr) by 2002:a17:90a:eac4:b0:2e2:8f4d:457 with SMTP id 98e67ed59e1d1-2e2c80b5015mr7266a91.2.1728584689990; Thu, 10 Oct 2024 11:24:49 -0700 (PDT) Date: Thu, 10 Oct 2024 11:23:03 -0700 In-Reply-To: <20241010182427.1434605-1-seanjc@google.com> 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: <20241010182427.1434605-2-seanjc@google.com> Subject: [PATCH v13 01/85] KVM: Drop KVM_ERR_PTR_BAD_PAGE and instead return NULL to indicate an error 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241010_112453_384894_7BA1492F X-CRM114-Status: GOOD ( 13.83 ) 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: , Reply-To: Sean Christopherson Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Remove KVM_ERR_PTR_BAD_PAGE and instead return NULL, as "bad page" is just a leftover bit of weirdness from days of old when KVM stuffed a "bad" page into the guest instead of actually handling missing pages. See commit cea7bb21280e ("KVM: MMU: Make gfn_to_page() always safe"). Reviewed-by: Alex Bennée Tested-by: Alex Bennée Signed-off-by: Sean Christopherson --- arch/powerpc/kvm/book3s_pr.c | 2 +- arch/powerpc/kvm/book3s_xive_native.c | 2 +- arch/s390/kvm/vsie.c | 2 +- arch/x86/kvm/lapic.c | 2 +- include/linux/kvm_host.h | 7 ------- virt/kvm/kvm_main.c | 15 ++++++--------- 6 files changed, 10 insertions(+), 20 deletions(-) diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index 7b8ae509328f..d7721297b9b6 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -645,7 +645,7 @@ static void kvmppc_patch_dcbz(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte) int i; hpage = gfn_to_page(vcpu->kvm, pte->raddr >> PAGE_SHIFT); - if (is_error_page(hpage)) + if (!hpage) return; hpage_offset = pte->raddr & ~PAGE_MASK; diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c index 6e2ebbd8aaac..d9bf1bc3ff61 100644 --- a/arch/powerpc/kvm/book3s_xive_native.c +++ b/arch/powerpc/kvm/book3s_xive_native.c @@ -654,7 +654,7 @@ static int kvmppc_xive_native_set_queue_config(struct kvmppc_xive *xive, } page = gfn_to_page(kvm, gfn); - if (is_error_page(page)) { + if (!page) { srcu_read_unlock(&kvm->srcu, srcu_idx); pr_err("Couldn't get queue page %llx!\n", kvm_eq.qaddr); return -EINVAL; diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index 89cafea4c41f..763a070f5955 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -661,7 +661,7 @@ static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa) struct page *page; page = gfn_to_page(kvm, gpa_to_gfn(gpa)); - if (is_error_page(page)) + if (!page) return -EINVAL; *hpa = (hpa_t)page_to_phys(page) + (gpa & ~PAGE_MASK); return 0; diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 2098dc689088..20526e4d6c62 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2664,7 +2664,7 @@ int kvm_alloc_apic_access_page(struct kvm *kvm) } page = gfn_to_page(kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT); - if (is_error_page(page)) { + if (!page) { ret = -EFAULT; goto out; } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index db567d26f7b9..ee186a1fbaad 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -153,13 +153,6 @@ static inline bool kvm_is_error_gpa(gpa_t gpa) return gpa == INVALID_GPA; } -#define KVM_ERR_PTR_BAD_PAGE (ERR_PTR(-ENOENT)) - -static inline bool is_error_page(struct page *page) -{ - return IS_ERR(page); -} - #define KVM_REQUEST_MASK GENMASK(7,0) #define KVM_REQUEST_NO_WAKEUP BIT(8) #define KVM_REQUEST_WAIT BIT(9) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 05cbb2548d99..4b659a649dfa 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3078,19 +3078,14 @@ EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic); */ struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn) { - struct page *page; kvm_pfn_t pfn; pfn = gfn_to_pfn(kvm, gfn); if (is_error_noslot_pfn(pfn)) - return KVM_ERR_PTR_BAD_PAGE; + return NULL; - page = kvm_pfn_to_refcounted_page(pfn); - if (!page) - return KVM_ERR_PTR_BAD_PAGE; - - return page; + return kvm_pfn_to_refcounted_page(pfn); } EXPORT_SYMBOL_GPL(gfn_to_page); @@ -3184,7 +3179,8 @@ static void kvm_set_page_accessed(struct page *page) void kvm_release_page_clean(struct page *page) { - WARN_ON(is_error_page(page)); + if (WARN_ON(!page)) + return; kvm_set_page_accessed(page); put_page(page); @@ -3208,7 +3204,8 @@ EXPORT_SYMBOL_GPL(kvm_release_pfn_clean); void kvm_release_page_dirty(struct page *page) { - WARN_ON(is_error_page(page)); + if (WARN_ON(!page)) + return; kvm_set_page_dirty(page); kvm_release_page_clean(page);