Commit 232e5522 authored by Chenyi Qiang's avatar Chenyi Qiang Committed by Aichun Shi
Browse files

KVM: X86: Rename DR6_INIT to DR6_ACTIVE_LOW 

mainline inclusion
from mainline-v5.12-rc1
commit 9a3ecd5e
category: feature
feature: KVM Bus Lock Debug Exception
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I5RHW7
CVE: N/A
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/


commit/?id=9a3ecd5e

Intel-SIG: commit 9a3ecd5e ("KVM: X86: Rename DR6_INIT to DR6_ACTIVE_LOW")

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

KVM: X86: Rename DR6_INIT to DR6_ACTIVE_LOW

DR6_INIT contains the 1-reserved bits as well as the bit that is cleared
to 0 when the condition (e.g. RTM) happens. The value can be used to
initialize dr6 and also be the XOR mask between the #DB exit
qualification (or payload) and DR6.

Concerning that DR6_INIT is used as initial value only once, rename it
to DR6_ACTIVE_LOW and apply it in other places, which would make the
incoming changes for bus lock debug exception more simple.

Signed-off-by: default avatarChenyi Qiang <chenyi.qiang@intel.com>
Message-Id: <20210202090433.13441-2-chenyi.qiang@intel.com>
[Define DR6_FIXED_1 from DR6_ACTIVE_LOW and DR6_VOLATILE. - Paolo]
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarAichun Shi <aichun.shi@intel.com>
parent fe26a9fc

arch/x86/include/asm/kvm_host.h

+10 −2
Original line number Diff line number Diff line
@@ -206,9 +206,17 @@ enum x86_intercept_stage; 
#define DR6_BS		(1 << 14)

#define DR6_BT		(1 << 15)

#define DR6_RTM		(1 << 16)

#define DR6_FIXED_1	0xfffe0ff0

#define DR6_INIT	0xffff0ff0

/*

 * DR6_ACTIVE_LOW combines fixed-1 and active-low bits.

 * We can regard all the bits in DR6_FIXED_1 as active_low bits;

 * they will never be 0 for now, but when they are defined

 * in the future it will require no code change.

 *

 * DR6_ACTIVE_LOW is also used as the init/reset value for DR6.

 */

#define DR6_ACTIVE_LOW	0xffff0ff0

#define DR6_VOLATILE	0x0001e00f

#define DR6_FIXED_1	(DR6_ACTIVE_LOW & ~DR6_VOLATILE)



#define DR7_BP_EN_MASK	0x000000ff

#define DR7_GE		(1 << 9)

arch/x86/kvm/emulate.c

+1 −1
Original line number Diff line number Diff line
@@ -4276,7 +4276,7 @@ static int check_dr_read(struct x86_emulate_ctxt *ctxt) 


		ctxt->ops->get_dr(ctxt, 6, &dr6);

		dr6 &= ~DR_TRAP_BITS;

		dr6 |= DR6_BD | DR6_RTM;

		dr6 |= DR6_BD | DR6_ACTIVE_LOW;

		ctxt->ops->set_dr(ctxt, 6, dr6);

		return emulate_db(ctxt);

	}

arch/x86/kvm/svm/nested.c

+1 −1
Original line number Diff line number Diff line
@@ -426,7 +426,7 @@ static void nested_prepare_vmcb_save(struct vcpu_svm *svm, struct vmcb *vmcb12) 
	svm->vmcb->save.rsp = vmcb12->save.rsp;

	svm->vmcb->save.rip = vmcb12->save.rip;

	svm->vmcb->save.dr7 = vmcb12->save.dr7 | DR7_FIXED_1;

	svm->vcpu.arch.dr6  = vmcb12->save.dr6 | DR6_FIXED_1 | DR6_RTM;

	svm->vcpu.arch.dr6  = vmcb12->save.dr6 | DR6_ACTIVE_LOW;

	svm->vmcb->save.cpl = vmcb12->save.cpl;

}

arch/x86/kvm/svm/svm.c

+3 −3
Original line number Diff line number Diff line
@@ -1788,7 +1788,7 @@ static void svm_sync_dirty_debug_regs(struct kvm_vcpu *vcpu) 
	get_debugreg(vcpu->arch.db[2], 2);

	get_debugreg(vcpu->arch.db[3], 3);

	/*

	 * We cannot reset svm->vmcb->save.dr6 to DR6_FIXED_1|DR6_RTM here,

	 * We cannot reset svm->vmcb->save.dr6 to DR6_ACTIVE_LOW here,

	 * because db_interception might need it.  We can do it before vmentry.

	 */

	vcpu->arch.dr6 = svm->vmcb->save.dr6;
@@ -1836,7 +1836,7 @@ static int db_interception(struct vcpu_svm *svm) 
	if (!(svm->vcpu.guest_debug &

	      (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) &&

		!svm->nmi_singlestep) {

		u32 payload = (svm->vmcb->save.dr6 ^ DR6_RTM) & ~DR6_FIXED_1;

		u32 payload = svm->vmcb->save.dr6 ^ DR6_ACTIVE_LOW;

		kvm_queue_exception_p(&svm->vcpu, DB_VECTOR, payload);

		return 1;

	}
@@ -3595,7 +3595,7 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu) 
	if (unlikely(svm->vcpu.arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT))

		svm_set_dr6(svm, vcpu->arch.dr6);

	else

		svm_set_dr6(svm, DR6_FIXED_1 | DR6_RTM);

		svm_set_dr6(svm, DR6_ACTIVE_LOW);



	clgi();

	kvm_load_guest_xsave_state(vcpu);

arch/x86/kvm/vmx/nested.c

+2 −2
Original line number Diff line number Diff line
@@ -413,8 +413,8 @@ static int nested_vmx_check_exception(struct kvm_vcpu *vcpu, unsigned long *exit 
		if (nr == DB_VECTOR) {

			if (!has_payload) {

				payload = vcpu->arch.dr6;

				payload &= ~(DR6_FIXED_1 | DR6_BT);

				payload ^= DR6_RTM;

				payload &= ~DR6_BT;

				payload ^= DR6_ACTIVE_LOW;

			}

			*exit_qual = payload;

		} else