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charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260428-gmem-inplace-conversion-v5-7-d8608ccfca22@google.com> References: <20260428-gmem-inplace-conversion-v5-0-d8608ccfca22@google.com> In-Reply-To: <20260428-gmem-inplace-conversion-v5-0-d8608ccfca22@google.com> To: aik@amd.com, andrew.jones@linux.dev, binbin.wu@linux.intel.com, brauner@kernel.org, chao.p.peng@linux.intel.com, david@kernel.org, ira.weiny@intel.com, jmattson@google.com, jthoughton@google.com, michael.roth@amd.com, oupton@kernel.org, pankaj.gupta@amd.com, qperret@google.com, rick.p.edgecombe@intel.com, rientjes@google.com, shivankg@amd.com, steven.price@arm.com, tabba@google.com, willy@infradead.org, wyihan@google.com, yan.y.zhao@intel.com, forkloop@google.com, pratyush@kernel.org, suzuki.poulose@arm.com, aneesh.kumar@kernel.org, Paolo Bonzini , Sean Christopherson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , Shuah Khan , Vishal Annapurve , Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Jason Gunthorpe , Vlastimil Babka Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, Ackerley Tng X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1777418714; l=5801; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=QPxDAv4i49Lp2kh12cGxu3WGIDzywKuUGdyQ/nfUisI=; b=H7Gk4J0tyHq3MQv7cJZbXEyzOJDX6sNaPQffh/1UX3d0J6XV3uP86zbyCK+G5WFmDwe9hN+76 0GodstiPPcuDHZU/9hc7J1GoIETKUrg15mUByBNAMgFhtDQkJk6f/4+ X-Developer-Key: i=ackerleytng@google.com; a=ed25519; pk=sAZDYXdm6Iz8FHitpHeFlCMXwabodTm7p8/3/8xUxuU= X-Endpoint-Received: by B4 Relay for ackerleytng@google.com/20260225 with auth_id=649 X-Original-From: Ackerley Tng Reply-To: ackerleytng@google.com X-Stat-Signature: pkkpdjieztteyftgkg9wjtdoq5xtzkmi X-Rspamd-Queue-Id: BB9B840004 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1777418721-503524 X-HE-Meta: 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 UVr3tAW4 MagN6FOYagB/L8WSrH08IIrgi63mUGz+e2ssrj7iSDH5CM1aU8CdgujFI+VSmD9VQ0xuffsF/hXl7TBzP3SIoj+mTD6rtUAW7+Lk7TF20dx7E/skyKSsNFUObs9fXe+BIGg1N8mSaerRNvPWIVdbSOnh8I156I3OWk7acULdwmhJJoqBIQgoTuqJRsqVqLR86euy6lgvDaPMJ5yfGc6U7sxP/PzwiC9Gm6nLfCfMx5i2LQbmiwzwyRoRfGapNL8pn3LVDxNYHnZjYWiAweStdfXj8maLy8qRmz2V7fQnb9QuEzvf2fNHsshl8K0ThLmwCIcYFcVP9mu0D/ZZ4G07k81BvDDKS27LycyNC26f35sOGD9mVYKcFHu4No4pRqRCYfMEb+19yLrkfczyxFda8ynhq1w19Cwj/LMqe80yGj847caa/KyxQTOv9/sgYFlkZUc0bMvx2v6rtA+ZjT/mcSkMs6Q== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Ackerley Tng Update the guest_memfd populate() flow to pull memory attributes from the gmem instance instead of the VM when KVM is not configured to track shared/private status in the VM. Rename the per-VM API to make it clear that it retrieves per-VM attributes, i.e. is not suitable for use outside of flows that are specific to generic per-VM attributes. Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Signed-off-by: Ackerley Tng --- arch/x86/kvm/mmu/mmu.c | 2 +- include/linux/kvm_host.h | 14 +++++++++++++- virt/kvm/guest_memfd.c | 24 +++++++++++++++++++++--- virt/kvm/kvm_main.c | 8 +++----- 4 files changed, 38 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 2cc848bddf190..d3da387340a9d 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -8004,7 +8004,7 @@ static bool hugepage_has_attrs(struct kvm *kvm, struct kvm_memory_slot *slot, const unsigned long end = start + KVM_PAGES_PER_HPAGE(level); if (level == PG_LEVEL_2M) - return kvm_range_has_memory_attributes(kvm, start, end, ~0, attrs); + return kvm_range_has_vm_memory_attributes(kvm, start, end, ~0, attrs); for (gfn = start; gfn < end; gfn += KVM_PAGES_PER_HPAGE(level - 1)) { if (hugepage_test_mixed(slot, gfn, level - 1) || diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 28a54298d27db..1deab76dc0a2c 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -2549,12 +2549,24 @@ static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn) #endif #ifdef CONFIG_KVM_VM_MEMORY_ATTRIBUTES -bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end, +extern bool vm_memory_attributes; +bool kvm_range_has_vm_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end, unsigned long mask, unsigned long attrs); bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm, struct kvm_gfn_range *range); bool kvm_arch_post_set_memory_attributes(struct kvm *kvm, struct kvm_gfn_range *range); +#else +#define vm_memory_attributes false +static inline bool kvm_range_has_vm_memory_attributes(struct kvm *kvm, + gfn_t start, gfn_t end, + unsigned long mask, + unsigned long attrs) +{ + WARN_ONCE(1, "Unexpected call to kvm_range_has_vm_memory_attributes()"); + + return false; +} #endif /* CONFIG_KVM_VM_MEMORY_ATTRIBUTES */ unsigned long kvm_gmem_get_memory_attributes(struct kvm *kvm, gfn_t gfn); diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index e56f89640d050..758ac24a0ff40 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -936,12 +936,31 @@ int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot, EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_gmem_get_pfn); #ifdef CONFIG_HAVE_KVM_ARCH_GMEM_POPULATE +static bool kvm_gmem_range_is_private(struct gmem_inode *gi, pgoff_t index, + size_t nr_pages, struct kvm *kvm, gfn_t gfn) +{ + pgoff_t end = index + nr_pages - 1; + void *entry; + + if (vm_memory_attributes) + return kvm_range_has_vm_memory_attributes(kvm, gfn, gfn + nr_pages, + KVM_MEMORY_ATTRIBUTE_PRIVATE, + KVM_MEMORY_ATTRIBUTE_PRIVATE); + + mt_for_each(&gi->attributes, entry, index, end) { + if (xa_to_value(entry) != KVM_MEMORY_ATTRIBUTE_PRIVATE) + return false; + } + + return true; +} static long __kvm_gmem_populate(struct kvm *kvm, struct kvm_memory_slot *slot, struct file *file, gfn_t gfn, struct page *src_page, kvm_gmem_populate_cb post_populate, void *opaque) { pgoff_t index = kvm_gmem_get_index(slot, gfn); + struct gmem_inode *gi; struct folio *folio; kvm_pfn_t pfn; int ret; @@ -956,9 +975,8 @@ static long __kvm_gmem_populate(struct kvm *kvm, struct kvm_memory_slot *slot, folio_unlock(folio); - if (!kvm_range_has_memory_attributes(kvm, gfn, gfn + 1, - KVM_MEMORY_ATTRIBUTE_PRIVATE, - KVM_MEMORY_ATTRIBUTE_PRIVATE)) { + gi = GMEM_I(file_inode(file)); + if (!kvm_gmem_range_is_private(gi, index, 1, kvm, gfn)) { ret = -EINVAL; goto out_put_folio; } diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 4139e903f756a..0a4024948711a 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -103,9 +103,7 @@ module_param(allow_unsafe_mappings, bool, 0444); #ifdef CONFIG_KVM_MEMORY_ATTRIBUTES #ifdef CONFIG_KVM_VM_MEMORY_ATTRIBUTES -static bool vm_memory_attributes = true; -#else -#define vm_memory_attributes false +bool vm_memory_attributes = true; #endif DEFINE_STATIC_CALL_RET0(__kvm_get_memory_attributes, kvm_get_memory_attributes_t); EXPORT_SYMBOL_FOR_KVM_INTERNAL(STATIC_CALL_KEY(__kvm_get_memory_attributes)); @@ -2450,7 +2448,7 @@ static unsigned long kvm_get_vm_memory_attributes(struct kvm *kvm, gfn_t gfn) * Returns true if _all_ gfns in the range [@start, @end) have attributes * such that the bits in @mask match @attrs. */ -bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end, +bool kvm_range_has_vm_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end, unsigned long mask, unsigned long attrs) { XA_STATE(xas, &kvm->mem_attr_array, start); @@ -2584,7 +2582,7 @@ static int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end, mutex_lock(&kvm->slots_lock); /* Nothing to do if the entire range has the desired attributes. */ - if (kvm_range_has_memory_attributes(kvm, start, end, ~0, attributes)) + if (kvm_range_has_vm_memory_attributes(kvm, start, end, ~0, attributes)) goto out_unlock; /* -- 2.54.0.545.g6539524ca2-goog