Commit f94db0c8 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

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: default avatarLai Jiangshan <jiangshan.ljs@antgroup.com>
Link: https://lore.kernel.org/r/20230216154115.710033-8-jiangshanlai@gmail.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent e6722d92

arch/x86/include/asm/kvm_host.h

+4 −4
Original line number Diff line number Diff line
@@ -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);

arch/x86/kvm/mmu/mmu.c

+2 −0
Original line number Diff line number Diff line
@@ -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. */