[RFC PATCH 02/19] kvm: x86: Add kvm_arch_vcpu_set_regs()

[Adalbert Lazar <alazar@bitdefender.com>]

From: Mihai Dontu <mdontu@bitdefender.com>

This is a version of kvm_arch_vcpu_ioctl_set_regs() which does not touch
the exceptions vector.

Signed-off-by: Mihai Dontu <mdontu@bitdefender.com>
---
 arch/x86/kvm/x86.c       | 34 ++++++++++++++++++++++++++++++++++
 include/linux/kvm_host.h |  1 +
 2 files changed, 35 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 87d3cb901935..1a7493982310 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7291,6 +7291,40 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 	return 0;
 }
 
+/*
+ * Similar to kvm_arch_vcpu_ioctl_set_regs() but it does not reset
+ * the exceptions
+ */
+void kvm_arch_vcpu_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+	vcpu->arch.emulate_regs_need_sync_from_vcpu = true;
+	vcpu->arch.emulate_regs_need_sync_to_vcpu = false;
+
+	kvm_register_write(vcpu, VCPU_REGS_RAX, regs->rax);
+	kvm_register_write(vcpu, VCPU_REGS_RBX, regs->rbx);
+	kvm_register_write(vcpu, VCPU_REGS_RCX, regs->rcx);
+	kvm_register_write(vcpu, VCPU_REGS_RDX, regs->rdx);
+	kvm_register_write(vcpu, VCPU_REGS_RSI, regs->rsi);
+	kvm_register_write(vcpu, VCPU_REGS_RDI, regs->rdi);
+	kvm_register_write(vcpu, VCPU_REGS_RSP, regs->rsp);
+	kvm_register_write(vcpu, VCPU_REGS_RBP, regs->rbp);
+#ifdef CONFIG_X86_64
+	kvm_register_write(vcpu, VCPU_REGS_R8, regs->r8);
+	kvm_register_write(vcpu, VCPU_REGS_R9, regs->r9);
+	kvm_register_write(vcpu, VCPU_REGS_R10, regs->r10);
+	kvm_register_write(vcpu, VCPU_REGS_R11, regs->r11);
+	kvm_register_write(vcpu, VCPU_REGS_R12, regs->r12);
+	kvm_register_write(vcpu, VCPU_REGS_R13, regs->r13);
+	kvm_register_write(vcpu, VCPU_REGS_R14, regs->r14);
+	kvm_register_write(vcpu, VCPU_REGS_R15, regs->r15);
+#endif
+
+	kvm_rip_write(vcpu, regs->rip);
+	kvm_set_rflags(vcpu, regs->rflags);
+
+	kvm_make_request(KVM_REQ_EVENT, vcpu);
+}
+
 void kvm_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l)
 {
 	struct kvm_segment cs;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 8c0664309815..48cd2d856132 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -748,6 +748,7 @@ 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);
 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);
 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
 				  struct kvm_sregs *sregs);
 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
-- 
2.12.2