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AJvYcCVGr84akZtAI5J7otsx3qR/hhpTc8Yql9z5xyhRyawna1LkjLnQs8iS7ZKX5WmnunNa0VbNZtOe7xy8zmzuRsix@lists.infradead.org X-Gm-Message-State: AOJu0Yyydn1J+gsv1YVc6Wdpj6ejC5KxKIkz3dRJi3vcr5j2zXaft8FW IXUNRtNfFHFMnKv2LfiGDhIwMsStsK58yaFAKHoI9cDwMFElVfCjw8PitjAP+WqoYALiy7EJO1h aSB5g2H6FnQU4Ml8Raw== X-Google-Smtp-Source: AGHT+IHG431C9Dkqi/qIYLv2PsF4AG9wTnpdTRpS5AhCVpzGRU9pbxvoEXa2dp5chGFByPGXrjbUxl1WoPU70v1o X-Received: from wmbfj12.prod.google.com ([2002:a05:600c:c8c:b0:43b:cdf0:8c03]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:1988:b0:439:a1c7:7b2d with SMTP id 5b1f17b1804b1-43bd29272a3mr53453075e9.4.1741258849608; Thu, 06 Mar 2025 03:00:49 -0800 (PST) Date: Thu, 6 Mar 2025 11:00:31 +0000 In-Reply-To: <20250306110038.3733649-1-vdonnefort@google.com> Mime-Version: 1.0 References: <20250306110038.3733649-1-vdonnefort@google.com> X-Mailer: git-send-email 2.48.1.711.g2feabab25a-goog Message-ID: <20250306110038.3733649-3-vdonnefort@google.com> Subject: [PATCH v2 2/9] KVM: arm64: Add a range to __pkvm_host_share_guest() From: Vincent Donnefort To: 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 Cc: qperret@google.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, kernel-team@android.com, Vincent Donnefort X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250306_030051_181596_FFDD0A64 X-CRM114-Status: GOOD ( 17.29 ) 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 In preparation for supporting stage-2 huge mappings for np-guest. Add a nr_pages argument to the __pkvm_host_share_guest hypercall. This range supports only two values: 1 or PMD_SIZE / PAGE_SIZE (that is 512 on a 4K-pages system). Signed-off-by: Vincent Donnefort diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h index 978f38c386ee..1abbab5e2ff8 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h @@ -39,7 +39,7 @@ int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages); int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages); int __pkvm_host_share_ffa(u64 pfn, u64 nr_pages); int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages); -int __pkvm_host_share_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu, +int __pkvm_host_share_guest(u64 pfn, u64 gfn, u64 nr_pages, struct pkvm_hyp_vcpu *vcpu, enum kvm_pgtable_prot prot); int __pkvm_host_unshare_guest(u64 gfn, struct pkvm_hyp_vm *hyp_vm); int __pkvm_host_relax_perms_guest(u64 gfn, struct pkvm_hyp_vcpu *vcpu, enum kvm_pgtable_prot prot); diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 2c37680d954c..e71601746935 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -249,7 +249,8 @@ static void handle___pkvm_host_share_guest(struct kvm_cpu_context *host_ctxt) { DECLARE_REG(u64, pfn, host_ctxt, 1); DECLARE_REG(u64, gfn, host_ctxt, 2); - DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 3); + DECLARE_REG(u64, nr_pages, host_ctxt, 3); + DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 4); struct pkvm_hyp_vcpu *hyp_vcpu; int ret = -EINVAL; @@ -264,7 +265,7 @@ static void handle___pkvm_host_share_guest(struct kvm_cpu_context *host_ctxt) if (ret) goto out; - ret = __pkvm_host_share_guest(pfn, gfn, hyp_vcpu, prot); + ret = __pkvm_host_share_guest(pfn, gfn, nr_pages, hyp_vcpu, prot); out: cpu_reg(host_ctxt, 1) = ret; } diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index 63968c7740c3..7e3a249149a0 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -60,6 +60,9 @@ static void hyp_unlock_component(void) hyp_spin_unlock(&pkvm_pgd_lock); } +#define for_each_hyp_page(start, size, page) \ + for (page = hyp_phys_to_page(start); page < hyp_phys_to_page((start) + (size)); page++) + static void *host_s2_zalloc_pages_exact(size_t size) { void *addr = hyp_alloc_pages(&host_s2_pool, get_order(size)); @@ -509,10 +512,25 @@ int host_stage2_idmap_locked(phys_addr_t addr, u64 size, static void __host_update_page_state(phys_addr_t addr, u64 size, enum pkvm_page_state state) { - phys_addr_t end = addr + size; + struct hyp_page *page; - for (; addr < end; addr += PAGE_SIZE) - hyp_phys_to_page(addr)->host_state = state; + for_each_hyp_page(addr, size, page) + page->host_state = state; +} + +static void __host_update_share_guest_count(u64 phys, u64 size, bool inc) +{ + struct hyp_page *page; + + for_each_hyp_page(phys, size, page) { + if (inc) { + WARN_ON(page->host_share_guest_count++ == U32_MAX); + } else { + WARN_ON(!page->host_share_guest_count--); + if (!page->host_share_guest_count) + page->host_state = PKVM_PAGE_OWNED; + } + } } int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id) @@ -627,16 +645,16 @@ static int check_page_state_range(struct kvm_pgtable *pgt, u64 addr, u64 size, static int __host_check_page_state_range(u64 addr, u64 size, enum pkvm_page_state state) { - u64 end = addr + size; + struct hyp_page *page; int ret; - ret = check_range_allowed_memory(addr, end); + ret = check_range_allowed_memory(addr, addr + size); if (ret) return ret; hyp_assert_lock_held(&host_mmu.lock); - for (; addr < end; addr += PAGE_SIZE) { - if (hyp_phys_to_page(addr)->host_state != state) + for_each_hyp_page(addr, size, page) { + if (page->host_state != state) return -EPERM; } @@ -686,10 +704,9 @@ static enum pkvm_page_state guest_get_page_state(kvm_pte_t pte, u64 addr) return pkvm_getstate(kvm_pgtable_stage2_pte_prot(pte)); } -static int __guest_check_page_state_range(struct pkvm_hyp_vcpu *vcpu, u64 addr, +static int __guest_check_page_state_range(struct pkvm_hyp_vm *vm, u64 addr, u64 size, enum pkvm_page_state state) { - struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu); struct check_walk_data d = { .desired = state, .get_page_state = guest_get_page_state, @@ -896,49 +913,83 @@ int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages) return ret; } -int __pkvm_host_share_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu, +static int __guest_check_transition_size(u64 phys, u64 ipa, u64 nr_pages, u64 *size) +{ + if (nr_pages == 1) { + *size = PAGE_SIZE; + return 0; + } + + /* We solely support PMD_SIZE huge-pages */ + if (nr_pages != (1 << (PMD_SHIFT - PAGE_SHIFT))) + return -EINVAL; + + if (!IS_ALIGNED(phys | ipa, PMD_SIZE)) + return -EINVAL; + + *size = PMD_SIZE; + return 0; +} + +int __pkvm_host_share_guest(u64 pfn, u64 gfn, u64 nr_pages, struct pkvm_hyp_vcpu *vcpu, enum kvm_pgtable_prot prot) { struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu); u64 phys = hyp_pfn_to_phys(pfn); u64 ipa = hyp_pfn_to_phys(gfn); + enum pkvm_page_state state; struct hyp_page *page; + u64 size; int ret; if (prot & ~KVM_PGTABLE_PROT_RWX) return -EINVAL; - ret = check_range_allowed_memory(phys, phys + PAGE_SIZE); + ret = __guest_check_transition_size(phys, ipa, nr_pages, &size); + if (ret) + return ret; + + ret = check_range_allowed_memory(phys, phys + size); if (ret) return ret; host_lock_component(); guest_lock_component(vm); - ret = __guest_check_page_state_range(vcpu, ipa, PAGE_SIZE, PKVM_NOPAGE); + ret = __guest_check_page_state_range(vm, ipa, size, PKVM_NOPAGE); if (ret) goto unlock; - page = hyp_phys_to_page(phys); - switch (page->host_state) { + state = hyp_phys_to_page(phys)->host_state; + for_each_hyp_page(phys, size, page) { + if (page->host_state != state) { + ret = -EPERM; + goto unlock; + } + } + + switch (state) { case PKVM_PAGE_OWNED: - WARN_ON(__host_set_page_state_range(phys, PAGE_SIZE, PKVM_PAGE_SHARED_OWNED)); + WARN_ON(__host_set_page_state_range(phys, size, PKVM_PAGE_SHARED_OWNED)); break; case PKVM_PAGE_SHARED_OWNED: - if (page->host_share_guest_count) - break; - /* Only host to np-guest multi-sharing is tolerated */ - WARN_ON(1); - fallthrough; + for_each_hyp_page(phys, size, page) { + /* Only host to np-guest multi-sharing is tolerated */ + if (WARN_ON(!page->host_share_guest_count)) { + ret = -EPERM; + goto unlock; + } + } + break; default: ret = -EPERM; goto unlock; } - WARN_ON(kvm_pgtable_stage2_map(&vm->pgt, ipa, PAGE_SIZE, phys, + WARN_ON(kvm_pgtable_stage2_map(&vm->pgt, ipa, size, phys, pkvm_mkstate(prot, PKVM_PAGE_SHARED_BORROWED), &vcpu->vcpu.arch.pkvm_memcache, 0)); - page->host_share_guest_count++; + __host_update_share_guest_count(phys, size, true); unlock: guest_unlock_component(vm); diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c index 930b677eb9b0..00fd9a524bf7 100644 --- a/arch/arm64/kvm/pkvm.c +++ b/arch/arm64/kvm/pkvm.c @@ -361,7 +361,7 @@ int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, return -EINVAL; lockdep_assert_held_write(&kvm->mmu_lock); - ret = kvm_call_hyp_nvhe(__pkvm_host_share_guest, pfn, gfn, prot); + ret = kvm_call_hyp_nvhe(__pkvm_host_share_guest, pfn, gfn, 1, prot); if (ret) { /* Is the gfn already mapped due to a racing vCPU? */ if (ret == -EPERM)