Commit b3f15ec3 authored by Mark Rutland's avatar Mark Rutland Committed by Marc Zyngier
Browse files

kvm: arm/arm64: Fold VHE entry/exit work into kvm_vcpu_run_vhe() 



With VHE, running a vCPU always requires the sequence:

1. kvm_arm_vhe_guest_enter();
2. kvm_vcpu_run_vhe();
3. kvm_arm_vhe_guest_exit()

... and as we invoke this from the shared arm/arm64 KVM code, 32-bit arm
has to provide stubs for all three functions.

To simplify the common code, and make it easier to make further
modifications to the arm64-specific portions in the near future, let's
fold kvm_arm_vhe_guest_enter() and kvm_arm_vhe_guest_exit() into
kvm_vcpu_run_vhe().

The 32-bit stubs for kvm_arm_vhe_guest_enter() and
kvm_arm_vhe_guest_exit() are removed, as they are no longer used. The
32-bit stub for kvm_vcpu_run_vhe() is left as-is.

There should be no functional change as a result of this patch.

Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200210114757.2889-1-mark.rutland@arm.com
parent 51b25694

arch/arm/include/asm/kvm_host.h

+0 −3
Original line number Diff line number Diff line
@@ -394,9 +394,6 @@ static inline void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu) {} 
static inline void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu) {}

static inline void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu) {}



static inline void kvm_arm_vhe_guest_enter(void) {}

static inline void kvm_arm_vhe_guest_exit(void) {}



#define KVM_BP_HARDEN_UNKNOWN		-1

#define KVM_BP_HARDEN_WA_NEEDED		0

#define KVM_BP_HARDEN_NOT_REQUIRED	1

arch/arm64/include/asm/kvm_host.h

+0 −32
Original line number Diff line number Diff line
@@ -628,38 +628,6 @@ static inline void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr) {} 
static inline void kvm_clr_pmu_events(u32 clr) {}

#endif



static inline void kvm_arm_vhe_guest_enter(void)

{

	local_daif_mask();



	/*

	 * Having IRQs masked via PMR when entering the guest means the GIC

	 * will not signal the CPU of interrupts of lower priority, and the

	 * only way to get out will be via guest exceptions.

	 * Naturally, we want to avoid this.

	 *

	 * local_daif_mask() already sets GIC_PRIO_PSR_I_SET, we just need a

	 * dsb to ensure the redistributor is forwards EL2 IRQs to the CPU.

	 */

	pmr_sync();

}



static inline void kvm_arm_vhe_guest_exit(void)

{

	/*

	 * local_daif_restore() takes care to properly restore PSTATE.DAIF

	 * and the GIC PMR if the host is using IRQ priorities.

	 */

	local_daif_restore(DAIF_PROCCTX_NOIRQ);



	/*

	 * When we exit from the guest we change a number of CPU configuration

	 * parameters, such as traps.  Make sure these changes take effect

	 * before running the host or additional guests.

	 */

	isb();

}



#define KVM_BP_HARDEN_UNKNOWN		-1

#define KVM_BP_HARDEN_WA_NEEDED		0

#define KVM_BP_HARDEN_NOT_REQUIRED	1

arch/arm64/kvm/hyp/switch.c

+37 −2
Original line number Diff line number Diff line
@@ -617,7 +617,7 @@ static void __hyp_text __pmu_switch_to_host(struct kvm_cpu_context *host_ctxt) 
}



/* Switch to the guest for VHE systems running in EL2 */

int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)

static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)

{

	struct kvm_cpu_context *host_ctxt;

	struct kvm_cpu_context *guest_ctxt;
@@ -670,7 +670,42 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) 


	return exit_code;

}

NOKPROBE_SYMBOL(kvm_vcpu_run_vhe);

NOKPROBE_SYMBOL(__kvm_vcpu_run_vhe);



int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)

{

	int ret;



	local_daif_mask();



	/*

	 * Having IRQs masked via PMR when entering the guest means the GIC

	 * will not signal the CPU of interrupts of lower priority, and the

	 * only way to get out will be via guest exceptions.

	 * Naturally, we want to avoid this.

	 *

	 * local_daif_mask() already sets GIC_PRIO_PSR_I_SET, we just need a

	 * dsb to ensure the redistributor is forwards EL2 IRQs to the CPU.

	 */

	pmr_sync();



	ret = __kvm_vcpu_run_vhe(vcpu);



	/*

	 * local_daif_restore() takes care to properly restore PSTATE.DAIF

	 * and the GIC PMR if the host is using IRQ priorities.

	 */

	local_daif_restore(DAIF_PROCCTX_NOIRQ);



	/*

	 * When we exit from the guest we change a number of CPU configuration

	 * parameters, such as traps.  Make sure these changes take effect

	 * before running the host or additional guests.

	 */

	isb();



	return ret;

}



/* Switch to the guest for legacy non-VHE systems */

int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu)

virt/kvm/arm/arm.c

+0 −2
Original line number Diff line number Diff line
@@ -797,9 +797,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) 
		guest_enter_irqoff();



		if (has_vhe()) {

			kvm_arm_vhe_guest_enter();

			ret = kvm_vcpu_run_vhe(vcpu);

			kvm_arm_vhe_guest_exit();

		} else {

			ret = kvm_call_hyp_ret(__kvm_vcpu_run_nvhe, vcpu);

		}

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