Re: [PATCH v3 7/8] KVM: x86: Introduce KVM_GET_SREGS2 / KVM_SET_SREGS2
From: Paolo Bonzini <pbonzini@redhat.com>
Date: 2021-06-10 15:06:13
Also in:
kvm, lkml
Subsystem:
kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
On 07/06/21 11:02, Maxim Levitsky wrote:
+static int __set_sregs2(struct kvm_vcpu *vcpu, struct kvm_sregs2 *sregs2)
+{
+ int mmu_reset_needed = 0;
+ bool valid_pdptrs = sregs2->flags & KVM_SREGS2_FLAGS_PDPTRS_VALID;
+ int i, ret;
+ if (sregs2->flags & ~KVM_SREGS2_FLAGS_PDPTRS_VALID)
+ return -EINVAL;
+
+ ret = __set_sregs_common(vcpu, (struct kvm_sregs *)sregs2,
+ &mmu_reset_needed, !valid_pdptrs);
+ if (ret)
+ return ret;
+
+ if (valid_pdptrs) {
+ if (!is_pae_paging(vcpu))
+ return -EINVAL;
+ if (vcpu->arch.guest_state_protected)
+ return -EINVAL;
+ for (i = 0 ; i < 4 ; i++)
+ kvm_pdptr_write(vcpu, i, sregs2->pdptrs[i]);
+
+ kvm_register_mark_dirty(vcpu, VCPU_EXREG_PDPTR);
+ mmu_reset_needed = 1;
+ }
+ if (mmu_reset_needed)
+ kvm_mmu_reset_context(vcpu);
+ return 0;
}It's a bit nicer if the checks are done early:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f20c7c06bd4a..c6f8fec78c53 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c@@ -10248,22 +10248,23 @@ static int __set_sregs2(struct kvm_vcpu *vcpu, struct kvm_sregs2 *sregs2) { int mmu_reset_needed = 0; bool valid_pdptrs = sregs2->flags & KVM_SREGS2_FLAGS_PDPTRS_VALID; + bool pae = (sregs2->cr0 & X86_CR0_PG) && (sregs2->cr4 & X86_CR4_PAE) && + !(sregs2->efer & EFER_LMA); int i, ret; if (sregs2->flags & ~KVM_SREGS2_FLAGS_PDPTRS_VALID) return -EINVAL; + if (valid_pdptrs && (!pae || vcpu->arch.guest_state_protected)) + return -EINVAL; + ret = __set_sregs_common(vcpu, (struct kvm_sregs *)sregs2, &mmu_reset_needed, !valid_pdptrs); if (ret) return ret; if (valid_pdptrs) { - if (!is_pae_paging(vcpu)) - return -EINVAL; - if (vcpu->arch.guest_state_protected) - return -EINVAL; - for (i = 0 ; i < 4 ; i++) + for (i = 0; i < 4 ; i++) kvm_pdptr_write(vcpu, i, sregs2->pdptrs[i]); kvm_register_mark_dirty(vcpu, VCPU_EXREG_PDPTR);
Paolo