diff mbox series

[v10,06/81] KVM: x86: add kvm_arch_vcpu_set_regs()

Message ID 20201125093600.2766-7-alazar@bitdefender.com (mailing list archive)
State New, archived
Headers show
Series VM introspection | expand

Commit Message

Adalbert Lazăr Nov. 25, 2020, 9:34 a.m. UTC 
From: Nicușor Cîțu <nicu.citu@icloud.com>

This is needed for the KVMI_VCPU_SET_REGISTERS command, which allows
an introspection tool to override the kvm_regs structure for a specific
vCPU without clearing the pending exception. In most cases this is used
to increment the program counter.

Signed-off-by: Nicușor Cîțu <nicu.citu@icloud.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/kvm/x86.c       | 21 ++++++++++++++-------
 include/linux/kvm_host.h |  2 ++
 2 files changed, 16 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 540e42341435..5951458408fb 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9406,16 +9406,23 @@  static void __set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 
 	kvm_rip_write(vcpu, regs->rip);
 	kvm_set_rflags(vcpu, regs->rflags | X86_EFLAGS_FIXED);
-
-	vcpu->arch.exception.pending = false;
-
-	kvm_make_request(KVM_REQ_EVENT, vcpu);
 }
 
-int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+void kvm_arch_vcpu_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs,
+			    bool clear_exception)
 {
-	vcpu_load(vcpu);
 	__set_regs(vcpu, regs);
+
+	if (clear_exception)
+		vcpu->arch.exception.pending = false;
+
+	kvm_make_request(KVM_REQ_EVENT, vcpu);
+}
+
+int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+	vcpu_load(vcpu);
+	kvm_arch_vcpu_set_regs(vcpu, regs, true);
 	vcpu_put(vcpu);
 	return 0;
 }
@@ -9816,7 +9823,7 @@  static int sync_regs(struct kvm_vcpu *vcpu)
 		return -EINVAL;
 
 	if (vcpu->run->kvm_dirty_regs & KVM_SYNC_X86_REGS) {
-		__set_regs(vcpu, &vcpu->run->s.regs.regs);
+		kvm_arch_vcpu_set_regs(vcpu, &vcpu->run->s.regs.regs, true);
 		vcpu->run->kvm_dirty_regs &= ~KVM_SYNC_X86_REGS;
 	}
 	if (vcpu->run->kvm_dirty_regs & KVM_SYNC_X86_SREGS) {
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 13c6b806477b..6d622d8bd339 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -904,6 +904,8 @@  int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs);
 void kvm_arch_vcpu_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs);
 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs);
+void kvm_arch_vcpu_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs,
+			    bool clear_exception);
 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
 				  struct kvm_sregs *sregs);
 void kvm_arch_vcpu_get_sregs(struct kvm_vcpu *vcpu,