Commit a2c046e4 authored by James Hogan's avatar James Hogan
Browse files

KVM: MIPS: Add vcpu_run() & vcpu_reenter() callbacks 



Add implementation callbacks for entering the guest (vcpu_run()) and
reentering the guest (vcpu_reenter()), allowing implementation specific
operations to be performed before entering the guest or after returning
to the host without cluttering kvm_arch_vcpu_ioctl_run().

This allows the T&E specific lazy user GVA flush to be moved into
trap_emul.c, along with disabling of the HTW. We also move
kvm_mips_deliver_interrupts() as VZ will need to restore the guest timer
state prior to delivering interrupts.

Signed-off-by: default avatarJames 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
parent c550d539

arch/mips/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -539,6 +539,8 @@ struct kvm_mips_callbacks { 
			   const struct kvm_one_reg *reg, s64 v);

	int (*vcpu_load)(struct kvm_vcpu *vcpu, int cpu);

	int (*vcpu_put)(struct kvm_vcpu *vcpu, int cpu);

	int (*vcpu_run)(struct kvm_run *run, struct kvm_vcpu *vcpu);

	void (*vcpu_reenter)(struct kvm_run *run, struct kvm_vcpu *vcpu);

};

extern struct kvm_mips_callbacks *kvm_mips_callbacks;

int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks);

arch/mips/kvm/mips.c

+2 −41
Original line number Diff line number Diff line
@@ -410,32 +410,6 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, 
	return -ENOIOCTLCMD;

}



/* Must be called with preemption disabled, just before entering guest */

static void kvm_mips_check_asids(struct kvm_vcpu *vcpu)

{

	struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;

	struct mips_coproc *cop0 = vcpu->arch.cop0;

	int i, cpu = smp_processor_id();

	unsigned int gasid;



	/*

	 * Lazy host ASID regeneration for guest user mode.

	 * If the guest ASID has changed since the last guest usermode

	 * execution, regenerate the host ASID so as to invalidate stale TLB

	 * entries.

	 */

	if (!KVM_GUEST_KERNEL_MODE(vcpu)) {

		gasid = kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID;

		if (gasid != vcpu->arch.last_user_gasid) {

			kvm_get_new_mmu_context(user_mm, cpu, vcpu);

			for_each_possible_cpu(i)

				if (i != cpu)

					cpu_context(i, user_mm) = 0;

			vcpu->arch.last_user_gasid = gasid;

		}

	}

}



int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)

{

	int r = 0;
@@ -453,25 +427,12 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) 
	lose_fpu(1);



	local_irq_disable();

	/* Check if we have any exceptions/interrupts pending */

	kvm_mips_deliver_interrupts(vcpu,

				    kvm_read_c0_guest_cause(vcpu->arch.cop0));



	guest_enter_irqoff();



	/* Disable hardware page table walking while in guest */

	htw_stop();



	trace_kvm_enter(vcpu);



	kvm_mips_check_asids(vcpu);

	r = kvm_mips_callbacks->vcpu_run(run, vcpu);



	r = vcpu->arch.vcpu_run(run, vcpu);

	trace_kvm_out(vcpu);



	/* Re-enable HTW before enabling interrupts */

	htw_start();



	guest_exit_irqoff();

	local_irq_enable();
@@ -1570,7 +1531,7 @@ skip_emul: 
	if (ret == RESUME_GUEST) {

		trace_kvm_reenter(vcpu);



		kvm_mips_check_asids(vcpu);

		kvm_mips_callbacks->vcpu_reenter(run, vcpu);



		/*

		 * If FPU / MSA are enabled (i.e. the guest's FPU / MSA context

arch/mips/kvm/trap_emul.c

+48 −0
Original line number Diff line number Diff line
@@ -692,6 +692,52 @@ static int kvm_trap_emul_vcpu_put(struct kvm_vcpu *vcpu, int cpu) 
	return 0;

}



static void kvm_trap_emul_vcpu_reenter(struct kvm_run *run,

				       struct kvm_vcpu *vcpu)

{

	struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;

	struct mips_coproc *cop0 = vcpu->arch.cop0;

	int i, cpu = smp_processor_id();

	unsigned int gasid;



	/*

	 * Lazy host ASID regeneration for guest user mode.

	 * If the guest ASID has changed since the last guest usermode

	 * execution, regenerate the host ASID so as to invalidate stale TLB

	 * entries.

	 */

	if (!KVM_GUEST_KERNEL_MODE(vcpu)) {

		gasid = kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID;

		if (gasid != vcpu->arch.last_user_gasid) {

			kvm_get_new_mmu_context(user_mm, cpu, vcpu);

			for_each_possible_cpu(i)

				if (i != cpu)

					cpu_context(i, user_mm) = 0;

			vcpu->arch.last_user_gasid = gasid;

		}

	}

}



static int kvm_trap_emul_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)

{

	int r;



	/* Check if we have any exceptions/interrupts pending */

	kvm_mips_deliver_interrupts(vcpu,

				    kvm_read_c0_guest_cause(vcpu->arch.cop0));



	kvm_trap_emul_vcpu_reenter(run, vcpu);



	/* Disable hardware page table walking while in guest */

	htw_stop();



	r = vcpu->arch.vcpu_run(run, vcpu);



	htw_start();



	return r;

}



static struct kvm_mips_callbacks kvm_trap_emul_callbacks = {

	/* exit handlers */

	.handle_cop_unusable = kvm_trap_emul_handle_cop_unusable,
@@ -724,6 +770,8 @@ static struct kvm_mips_callbacks kvm_trap_emul_callbacks = { 
	.set_one_reg = kvm_trap_emul_set_one_reg,

	.vcpu_load = kvm_trap_emul_vcpu_load,

	.vcpu_put = kvm_trap_emul_vcpu_put,

	.vcpu_run = kvm_trap_emul_vcpu_run,

	.vcpu_reenter = kvm_trap_emul_vcpu_reenter,

};



int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks)

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