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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=1778185365; l=7274; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=EYgKcaGJy43Vv1gUJyi959Hx8yU8hB2vLuSQuVzjHc8=; b=mI2ReXmtjKSxVCTSRHg+SnxUFY6j3CgHvtQUTQW6HwOtRBOyFa6u3pGvUWHTW428t+iHAB4Qj /goa9A33Q3UDJkchUNdXFGdcLfNjSu7wIKttkOUIwjpeXkT+q4OfF/B 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: rg5fr9hfnriibeqcompp5eqrins3ye83 X-Rspamd-Queue-Id: DAE1BA0003 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1778185369-638530 X-HE-Meta: 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 /7ic1URO H3rGktYg1ctzEBR2nmz6WwbJZ/uK4yjsqRkSEJu8I0UBX0Qj+433Y/bxzJEtNuPOs746eqdNWdVEn05vXDVjvumJFtNPXlXenTghkTqV8Gfh0rqVzvvntgZfLWt8Lnhy8kayXrdFYBq1hEwzjSNeapApZKgKI2ach5fhwFY/69+XP38W/ZEf2Wn3eFplgjCJrhX/jarg9e/RcagjM1ar+8B5v2er/z2IBuxTMd+B6u/fA3HOD5yMIyCUEPwcEKJmbycUA/v9XQyDpbB1ojHcWw871HLfn0JLpVS31vCHgCKuWTOGqwyTsWXrU9STp+e0ollkr6XTDSiQ37vflpSz/7hxXwtxTOI0g6fbUwklyz6zggCp6iXF8jBlP0JBol5QG39ZS8Wq8SEr7sPCL50eeu4GQm2vpN0Y52OBJ Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Sean Christopherson Introduce the basic infrastructure to allow per-VM memory attribute tracking to be disabled. This will be built-upon in a later patch, where a module param can disable per-VM memory attribute tracking. Split the Kconfig option into a base KVM_MEMORY_ATTRIBUTES and the existing KVM_VM_MEMORY_ATTRIBUTES. The base option provides the core plumbing, while the latter enables the full per-VM tracking via an xarray and the associated ioctls. kvm_get_memory_attributes() now performs a static call that either looks up kvm->mem_attr_array with CONFIG_KVM_VM_MEMORY_ATTRIBUTES is enabled, or just returns 0 otherwise. The static call can be patched depending on whether per-VM tracking is enabled by the CONFIG. No functional change intended. Signed-off-by: Sean Christopherson Signed-off-by: Ackerley Tng --- arch/x86/include/asm/kvm_host.h | 2 +- include/linux/kvm_host.h | 23 ++++++++++++--------- virt/kvm/Kconfig | 4 ++++ virt/kvm/kvm_main.c | 44 ++++++++++++++++++++++++++++++++++++++++- 4 files changed, 62 insertions(+), 11 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 60b997764beef..c9aa50bcdac2d 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -2369,7 +2369,7 @@ void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, int tdp_max_root_level, int tdp_huge_page_level); -#ifdef CONFIG_KVM_VM_MEMORY_ATTRIBUTES +#ifdef CONFIG_KVM_MEMORY_ATTRIBUTES #define kvm_arch_has_private_mem(kvm) ((kvm)->arch.has_private_mem) #endif diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 7d079f9701346..c5ba2cb34e45c 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -2528,19 +2528,15 @@ static inline bool kvm_memslot_is_gmem_only(const struct kvm_memory_slot *slot) return slot->flags & KVM_MEMSLOT_GMEM_ONLY; } -#ifdef CONFIG_KVM_VM_MEMORY_ATTRIBUTES +#ifdef CONFIG_KVM_MEMORY_ATTRIBUTES +typedef unsigned long (kvm_get_memory_attributes_t)(struct kvm *kvm, gfn_t gfn); +DECLARE_STATIC_CALL(__kvm_get_memory_attributes, kvm_get_memory_attributes_t); + static inline unsigned long kvm_get_memory_attributes(struct kvm *kvm, gfn_t gfn) { - return xa_to_value(xa_load(&kvm->mem_attr_array, gfn)); + return static_call(__kvm_get_memory_attributes)(kvm, gfn); } -bool kvm_range_has_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); - static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn) { return kvm_get_memory_attributes(kvm, gfn) & KVM_MEMORY_ATTRIBUTE_PRIVATE; @@ -2550,6 +2546,15 @@ static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn) { return false; } +#endif + +#ifdef CONFIG_KVM_VM_MEMORY_ATTRIBUTES +bool kvm_range_has_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); #endif /* CONFIG_KVM_VM_MEMORY_ATTRIBUTES */ #ifdef CONFIG_KVM_GUEST_MEMFD diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index 5119cb37145fc..3fea89c45cfb4 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -100,7 +100,11 @@ config KVM_ELIDE_TLB_FLUSH_IF_YOUNG config KVM_MMU_LOCKLESS_AGING bool +config KVM_MEMORY_ATTRIBUTES + bool + config KVM_VM_MEMORY_ATTRIBUTES + select KVM_MEMORY_ATTRIBUTES bool config KVM_GUEST_MEMFD diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index abb9cfa3eb04d..ee26f1d9b5fda 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -101,6 +101,17 @@ EXPORT_SYMBOL_FOR_KVM_INTERNAL(halt_poll_ns_shrink); static bool __ro_after_init allow_unsafe_mappings; 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 +#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)); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(STATIC_CALL_TRAMP(__kvm_get_memory_attributes)); +#endif + /* * Ordering of locks: * @@ -2418,7 +2429,7 @@ static int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm, } #endif /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */ -#ifdef CONFIG_KVM_VM_MEMORY_ATTRIBUTES +#ifdef CONFIG_KVM_MEMORY_ATTRIBUTES static u64 kvm_supported_mem_attributes(struct kvm *kvm) { #ifdef kvm_arch_has_private_mem @@ -2429,6 +2440,12 @@ static u64 kvm_supported_mem_attributes(struct kvm *kvm) return 0; } +#ifdef CONFIG_KVM_VM_MEMORY_ATTRIBUTES +static unsigned long kvm_get_vm_memory_attributes(struct kvm *kvm, gfn_t gfn) +{ + return xa_to_value(xa_load(&kvm->mem_attr_array, gfn)); +} + /* * Returns true if _all_ gfns in the range [@start, @end) have attributes * such that the bits in @mask match @attrs. @@ -2625,7 +2642,24 @@ static int kvm_vm_ioctl_set_mem_attributes(struct kvm *kvm, return kvm_vm_set_mem_attributes(kvm, start, end, attrs->attributes); } +#else /* CONFIG_KVM_VM_MEMORY_ATTRIBUTES */ +static unsigned long kvm_get_vm_memory_attributes(struct kvm *kvm, gfn_t gfn) +{ + BUILD_BUG_ON(1); +} #endif /* CONFIG_KVM_VM_MEMORY_ATTRIBUTES */ +static void kvm_init_memory_attributes(void) +{ + if (vm_memory_attributes) + static_call_update(__kvm_get_memory_attributes, + kvm_get_vm_memory_attributes); + else + static_call_update(__kvm_get_memory_attributes, + (void *)__static_call_return0); +} +#else /* CONFIG_KVM_MEMORY_ATTRIBUTES */ +static void kvm_init_memory_attributes(void) { } +#endif /* CONFIG_KVM_MEMORY_ATTRIBUTES */ struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn) { @@ -4925,6 +4959,9 @@ static int kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg) return 1; #ifdef CONFIG_KVM_VM_MEMORY_ATTRIBUTES case KVM_CAP_MEMORY_ATTRIBUTES: + if (!vm_memory_attributes) + return 0; + return kvm_supported_mem_attributes(kvm); #endif #ifdef CONFIG_KVM_GUEST_MEMFD @@ -5331,6 +5368,10 @@ static long kvm_vm_ioctl(struct file *filp, case KVM_SET_MEMORY_ATTRIBUTES: { struct kvm_memory_attributes attrs; + r = -ENOTTY; + if (!vm_memory_attributes) + goto out; + r = -EFAULT; if (copy_from_user(&attrs, argp, sizeof(attrs))) goto out; @@ -6527,6 +6568,7 @@ int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module) kvm_preempt_ops.sched_in = kvm_sched_in; kvm_preempt_ops.sched_out = kvm_sched_out; + kvm_init_memory_attributes(); kvm_init_debug(); r = kvm_vfio_ops_init(); -- 2.54.0.563.g4f69b47b94-goog