Commit 7183b2b5 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: Move pkvm's special 32bit handling into a generic infrastructure 



Protected KVM is trying to turn AArch32 exceptions into an illegal
exception entry. Unfortunately, it does that in a way that is a bit
abrupt, and too early for PSTATE to be available.

Instead, move it to the fixup code, which is a more reasonable place
for it. This will also be useful for the NV code.

Reviewed-by: default avatarFuad Tabba <tabba@google.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 83bb2c1a

arch/arm64/kvm/hyp/include/hyp/switch.h

+8 −0
Original line number Diff line number Diff line
@@ -403,6 +403,8 @@ typedef bool (*exit_handler_fn)(struct kvm_vcpu *, u64 *); 


static const exit_handler_fn *kvm_get_exit_handler_array(struct kvm_vcpu *vcpu);



static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code);



/*

 * Allow the hypervisor to handle the exit with an exit handler if it has one.

 *
@@ -435,6 +437,12 @@ static inline bool fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code) 
	 */

	vcpu->arch.ctxt.regs.pstate = read_sysreg_el2(SYS_SPSR);



	/*

	 * Check whether we want to repaint the state one way or

	 * another.

	 */

	early_exit_filter(vcpu, exit_code);



	if (ARM_EXCEPTION_CODE(*exit_code) != ARM_EXCEPTION_IRQ)

		vcpu->arch.fault.esr_el2 = read_sysreg_el2(SYS_ESR);

arch/arm64/kvm/hyp/nvhe/switch.c

+1 −7
Original line number Diff line number Diff line
@@ -233,7 +233,7 @@ static const exit_handler_fn *kvm_get_exit_handler_array(struct kvm_vcpu *vcpu) 
 * Returns false if the guest ran in AArch32 when it shouldn't have, and

 * thus should exit to the host, or true if a the guest run loop can continue.

 */

static bool handle_aarch32_guest(struct kvm_vcpu *vcpu, u64 *exit_code)

static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code)

{

	struct kvm *kvm = kern_hyp_va(vcpu->kvm);
@@ -248,10 +248,7 @@ static bool handle_aarch32_guest(struct kvm_vcpu *vcpu, u64 *exit_code) 
		vcpu->arch.target = -1;

		*exit_code &= BIT(ARM_EXIT_WITH_SERROR_BIT);

		*exit_code |= ARM_EXCEPTION_IL;

		return false;

	}



	return true;

}



/* Switch to the guest for legacy non-VHE systems */
@@ -316,9 +313,6 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu) 
		/* Jump in the fire! */

		exit_code = __guest_enter(vcpu);



		if (unlikely(!handle_aarch32_guest(vcpu, &exit_code)))

			break;



		/* And we're baaack! */

	} while (fixup_guest_exit(vcpu, &exit_code));

arch/arm64/kvm/hyp/vhe/switch.c

+4 −0
Original line number Diff line number Diff line
@@ -112,6 +112,10 @@ static const exit_handler_fn *kvm_get_exit_handler_array(struct kvm_vcpu *vcpu) 
	return hyp_exit_handlers;

}



static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code)

{

}



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

static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)

{