KVM: x86/mmu: Avoid mixing gpa_t with gfn_t in walk_addr_generic() (312d16c7) · Commits · 戴 / test

translate_gpa() returns a GPA, assigning it to 'real_gfn' seems obviously wrong. There is no real issue because both 'gpa_t' and 'gfn_t' are u64 and we don't use the value in 'real_gfn' as a GFN, we do real_gfn = gpa_to_gfn(real_gfn); instead. 'If you see a "buffalo" sign on an elephant's cage, do not trust your eyes', but let's fix it for good. No functional change intended. Signed-off-by:

Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200622151435.752560-1-vkuznets@redhat.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu/paging_tmpl.h

+3 −6

Original line number	Diff line number	Diff line
		@@ -360,7 +360,6 @@ retry_walk:
		++walker->level;

		do {
		gfn_t real_gfn;
		unsigned long host_addr;

		pt_access = pte_access;
		@@ -375,7 +374,7 @@ retry_walk:
		walker->table_gfn[walker->level - 1] = table_gfn;
		walker->pte_gpa[walker->level - 1] = pte_gpa;

		real_gfn = mmu->translate_gpa(vcpu, gfn_to_gpa(table_gfn),
		real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(table_gfn),
		nested_access,
		&walker->fault);

		@@ -389,12 +388,10 @@ retry_walk:
		* information to fix the exit_qualification or exit_info_1
		* fields.
		*/
		if (unlikely(real_gfn == UNMAPPED_GVA))
		if (unlikely(real_gpa == UNMAPPED_GVA))
		return 0;

		real_gfn = gpa_to_gfn(real_gfn);

		host_addr = kvm_vcpu_gfn_to_hva_prot(vcpu, real_gfn,
		host_addr = kvm_vcpu_gfn_to_hva_prot(vcpu, gpa_to_gfn(real_gpa),
		&walker->pte_writable[walker->level - 1]);
		if (unlikely(kvm_is_error_hva(host_addr)))
		goto error;

Admin message