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Fri, 26 Jul 2024 16:55:17 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 26 Jul 2024 16:52:26 -0700 In-Reply-To: <20240726235234.228822-1-seanjc@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240726235234.228822-1-seanjc@google.com> X-Mailer: git-send-email 2.46.0.rc1.232.g9752f9e123-goog Message-ID: <20240726235234.228822-78-seanjc@google.com> Subject: [PATCH v12 77/84] KVM: PPC: Explicitly require struct page memory for Ultravisor sharing 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, David Matlack , David Stevens Explicitly require "struct page" memory when sharing memory between guest and host via an Ultravisor. Given the number of pfn_to_page() calls in the code, it's safe to assume that KVM already requires that the pfn returned by gfn_to_pfn() is backed by struct page, i.e. this is likely a bug fix, not a reduction in KVM capabilities. Switching to gfn_to_page() will eventually allow removing gfn_to_pfn() and kvm_pfn_to_refcounted_page(). Signed-off-by: Sean Christopherson --- arch/powerpc/kvm/book3s_hv_uvmem.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index 92f33115144b..3a6592a31a10 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -879,9 +879,8 @@ static unsigned long kvmppc_share_page(struct kvm *kvm, unsigned long gpa, { int ret = H_PARAMETER; - struct page *uvmem_page; + struct page *page, *uvmem_page; struct kvmppc_uvmem_page_pvt *pvt; - unsigned long pfn; unsigned long gfn = gpa >> page_shift; int srcu_idx; unsigned long uvmem_pfn; @@ -901,8 +900,8 @@ static unsigned long kvmppc_share_page(struct kvm *kvm, unsigned long gpa, retry: mutex_unlock(&kvm->arch.uvmem_lock); - pfn = gfn_to_pfn(kvm, gfn); - if (is_error_noslot_pfn(pfn)) + page = gfn_to_page(kvm, gfn); + if (!page) goto out; mutex_lock(&kvm->arch.uvmem_lock); @@ -911,16 +910,16 @@ static unsigned long kvmppc_share_page(struct kvm *kvm, unsigned long gpa, pvt = uvmem_page->zone_device_data; pvt->skip_page_out = true; pvt->remove_gfn = false; /* it continues to be a valid GFN */ - kvm_release_pfn_clean(pfn); + kvm_release_page_unused(page); goto retry; } - if (!uv_page_in(kvm->arch.lpid, pfn << page_shift, gpa, 0, + if (!uv_page_in(kvm->arch.lpid, page_to_pfn(page) << page_shift, gpa, 0, page_shift)) { kvmppc_gfn_shared(gfn, kvm); ret = H_SUCCESS; } - kvm_release_pfn_clean(pfn); + kvm_release_page_clean(page); mutex_unlock(&kvm->arch.uvmem_lock); out: srcu_read_unlock(&kvm->srcu, srcu_idx); @@ -1083,21 +1082,21 @@ kvmppc_h_svm_page_out(struct kvm *kvm, unsigned long gpa, int kvmppc_send_page_to_uv(struct kvm *kvm, unsigned long gfn) { - unsigned long pfn; + struct page *page; int ret = U_SUCCESS; - pfn = gfn_to_pfn(kvm, gfn); - if (is_error_noslot_pfn(pfn)) + page = gfn_to_page(kvm, gfn); + if (!page) return -EFAULT; mutex_lock(&kvm->arch.uvmem_lock); if (kvmppc_gfn_is_uvmem_pfn(gfn, kvm, NULL)) goto out; - ret = uv_page_in(kvm->arch.lpid, pfn << PAGE_SHIFT, gfn << PAGE_SHIFT, - 0, PAGE_SHIFT); + ret = uv_page_in(kvm->arch.lpid, page_to_pfn(page) << PAGE_SHIFT, + gfn << PAGE_SHIFT, 0, PAGE_SHIFT); out: - kvm_release_pfn_clean(pfn); + kvm_release_page_clean(page); mutex_unlock(&kvm->arch.uvmem_lock); return (ret == U_SUCCESS) ? RESUME_GUEST : -EFAULT; }