From f94db0c8b9fa50296d00e236e2416aea11186e18 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 16 Feb 2023 23:41:13 +0800 Subject: [PATCH] KVM: x86/mmu: Sanity check input to kvm_mmu_free_roots() Tweak KVM_MMU_ROOTS_ALL to precisely cover all current+previous root flags, and add a sanity in kvm_mmu_free_roots() to verify that the set of roots to free doesn't stray outside KVM_MMU_ROOTS_ALL. Signed-off-by: Lai Jiangshan Link: https://lore.kernel.org/r/20230216154115.710033-8-jiangshanlai@gmail.com Signed-off-by: Sean Christopherson --- arch/x86/include/asm/kvm_host.h | 8 ++++---- arch/x86/kvm/mmu/mmu.c | 2 ++ 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index b7526c1..c23c49e 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -420,6 +420,10 @@ struct kvm_mmu_root_info { #define KVM_MMU_NUM_PREV_ROOTS 3 +#define KVM_MMU_ROOT_CURRENT BIT(0) +#define KVM_MMU_ROOT_PREVIOUS(i) BIT(1+i) +#define KVM_MMU_ROOTS_ALL (BIT(1 + KVM_MMU_NUM_PREV_ROOTS) - 1) + #define KVM_HAVE_MMU_RWLOCK struct kvm_mmu_page; @@ -1997,10 +2001,6 @@ static inline int __kvm_irq_line_state(unsigned long *irq_state, return !!(*irq_state); } -#define KVM_MMU_ROOT_CURRENT BIT(0) -#define KVM_MMU_ROOT_PREVIOUS(i) BIT(1+i) -#define KVM_MMU_ROOTS_ALL (~0UL) - int kvm_pic_set_irq(struct kvm_pic *pic, int irq, int irq_source_id, int level); void kvm_pic_clear_all(struct kvm_pic *pic, int irq_source_id); diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index cb01e01..ffc18f5 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3568,6 +3568,8 @@ void kvm_mmu_free_roots(struct kvm *kvm, struct kvm_mmu *mmu, LIST_HEAD(invalid_list); bool free_active_root; + WARN_ON_ONCE(roots_to_free & ~KVM_MMU_ROOTS_ALL); + BUILD_BUG_ON(KVM_MMU_NUM_PREV_ROOTS >= BITS_PER_LONG); /* Before acquiring the MMU lock, see if we need to do any real work. */ -- 2.7.4