Commit 265cc29f authored by Hao Xiang's avatar Hao Xiang Committed by Aichun Shi
Browse files

KVM: VMX: Remove redundant handling of bus lock vmexit 

mainline inclusion
from mainline-v5.15-rc7
commit d61863c6
category: feature
feature: KVM Bus Lock VM Exit
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I5RJCB
CVE: N/A
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/


commit/?id=d61863c6

Intel-SIG: commit d61863c6 ("KVM: VMX: Remove redundant handling of bus lock vmexit")

-------------------------------------

KVM: VMX: Remove redundant handling of bus lock vmexit

Hardware may or may not set exit_reason.bus_lock_detected on BUS_LOCK
VM-Exits. Dealing with KVM_RUN_X86_BUS_LOCK in handle_bus_lock_vmexit
could be redundant when exit_reason.basic is EXIT_REASON_BUS_LOCK.

We can remove redundant handling of bus lock vmexit. Unconditionally Set
exit_reason.bus_lock_detected in handle_bus_lock_vmexit(), and deal with
KVM_RUN_X86_BUS_LOCK only in vmx_handle_exit().

Signed-off-by: default avatarHao Xiang <hao.xiang@linux.alibaba.com>
Message-Id: <1634299161-30101-1-git-send-email-hao.xiang@linux.alibaba.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarAichun Shi <aichun.shi@intel.com>
parent 78e6cda7

arch/x86/kvm/vmx/vmx.c

+9 −6
Original line number Diff line number Diff line
@@ -5949,9 +5949,13 @@ static int handle_encls(struct kvm_vcpu *vcpu) 


static int handle_bus_lock_vmexit(struct kvm_vcpu *vcpu)

{

	vcpu->run->exit_reason = KVM_EXIT_X86_BUS_LOCK;

	vcpu->run->flags |= KVM_RUN_X86_BUS_LOCK;

	return 0;

	/*

	 * Hardware may or may not set the BUS_LOCK_DETECTED flag on BUS_LOCK

	 * VM-Exits. Unconditionally set the flag here and leave the handling to

	 * vmx_handle_exit().

	 */

	to_vmx(vcpu)->exit_reason.bus_lock_detected = true;

	return 1;

}



/*
@@ -6427,9 +6431,8 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath) 
	int ret = __vmx_handle_exit(vcpu, exit_fastpath);



	/*

	 * Even when current exit reason is handled by KVM internally, we

	 * still need to exit to user space when bus lock detected to inform

	 * that there is a bus lock in guest.

	 * Exit to user space when bus lock detected to inform that there is

	 * a bus lock in guest.

	 */

	if (to_vmx(vcpu)->exit_reason.bus_lock_detected) {

		if (ret > 0)