KVM: MIPS: Update exit handler for VZ (ea1bdbf6) · Commits · 戴 / test

The general guest exit handler needs a few tweaks for VZ compared to trap & emulate, which for now are made directly depending on CONFIG_KVM_MIPS_VZ: - There is no need to re-enable the hardware page table walker (HTW), as it can be left enabled during guest mode operation with VZ. - There is no need to perform a privilege check, as any guest privilege violations should have already been detected by the hardware and triggered the appropriate guest exception. Signed-off-by:

James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org

arch/mips/kvm/mips.c

+18 −13

Original line number	Diff line number	Diff line
		@@ -1230,6 +1230,7 @@ int kvm_mips_handle_exit(struct kvm_run run, struct kvm_vcpu vcpu)
		vcpu->mode = OUTSIDE_GUEST_MODE;

		/* re-enable HTW before enabling interrupts */
		if (!IS_ENABLED(CONFIG_KVM_MIPS_VZ))
		htw_start();

		/* Set a default exit reason */
		@@ -1248,9 +1249,11 @@ int kvm_mips_handle_exit(struct kvm_run run, struct kvm_vcpu vcpu)
		cause, opc, run, vcpu);
		trace_kvm_exit(vcpu, exccode);

		if (!IS_ENABLED(CONFIG_KVM_MIPS_VZ)) {
		/*
		* Do a privilege check, if in UM most of these exit conditions end up
		* causing an exception to be delivered to the Guest Kernel
		* Do a privilege check, if in UM most of these exit conditions
		* end up causing an exception to be delivered to the Guest
		* Kernel
		*/
		er = kvm_mips_check_privilege(cause, opc, run, vcpu);
		if (er == EMULATE_PRIV_FAIL) {
		@@ -1260,6 +1263,7 @@ int kvm_mips_handle_exit(struct kvm_run run, struct kvm_vcpu vcpu)
		ret = RESUME_HOST;
		goto skip_emul;
		}
		}

		switch (exccode) {
		case EXCCODE_INT:
		@@ -1418,6 +1422,7 @@ skip_emul:
		}

		/* Disable HTW before returning to guest or host */
		if (!IS_ENABLED(CONFIG_KVM_MIPS_VZ))
		htw_stop();

		return ret;

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