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Commit 02c83209 authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: Don't require explicit indication of completion of mmio or pio 



It is illegal not to return from a pio or mmio request without completing
it, as mmio or pio is an atomic operation.  Therefore, we can simplify
the userspace interface by avoiding the completion indication.

Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent e7df56e4

drivers/kvm/kvm_main.c

+22 −22
Original line number Original line Diff line number Diff line
@@ -1237,8 +1237,10 @@ int emulate_instruction(struct kvm_vcpu *vcpu, 
	kvm_arch_ops->decache_regs(vcpu);

	kvm_arch_ops->decache_regs(vcpu);

	kvm_arch_ops->set_rflags(vcpu, emulate_ctxt.eflags);

	kvm_arch_ops->set_rflags(vcpu, emulate_ctxt.eflags);





	if (vcpu->mmio_is_write)

	if (vcpu->mmio_is_write) {

		vcpu->mmio_needed = 0;

		return EMULATE_DO_MMIO;

		return EMULATE_DO_MMIO;

	}





	return EMULATE_DONE;

	return EMULATE_DONE;

}

}
@@ -1692,8 +1694,6 @@ static int complete_pio(struct kvm_vcpu *vcpu) 
			vcpu->regs[VCPU_REGS_RSI] += delta;

			vcpu->regs[VCPU_REGS_RSI] += delta;

	}

	}





	vcpu->run->io_completed = 0;



	kvm_arch_ops->decache_regs(vcpu);

	kvm_arch_ops->decache_regs(vcpu);





	io->count -= io->cur_count;

	io->count -= io->cur_count;
@@ -1800,12 +1800,13 @@ static int kvm_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	/* re-sync apic's tpr */

	/* re-sync apic's tpr */

	vcpu->cr8 = kvm_run->cr8;

	vcpu->cr8 = kvm_run->cr8;





	if (kvm_run->io_completed) {

	if (vcpu->pio.cur_count) {

	if (vcpu->pio.cur_count) {

		r = complete_pio(vcpu);

		r = complete_pio(vcpu);

		if (r)

		if (r)

			goto out;

			goto out;

		} else if (!vcpu->mmio_is_write) {

	}



	if (vcpu->mmio_needed) {

		memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);

		memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);

		vcpu->mmio_read_completed = 1;

		vcpu->mmio_read_completed = 1;

		vcpu->mmio_needed = 0;

		vcpu->mmio_needed = 0;
@@ -1820,7 +1821,6 @@ static int kvm_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
			goto out;

			goto out;

		}

		}

	}

	}

	}





	if (kvm_run->exit_reason == KVM_EXIT_HYPERCALL) {

	if (kvm_run->exit_reason == KVM_EXIT_HYPERCALL) {

		kvm_arch_ops->cache_regs(vcpu);

		kvm_arch_ops->cache_regs(vcpu);

include/linux/kvm.h

+2 −3
Original line number Original line Diff line number Diff line
@@ -11,7 +11,7 @@ 
#include <asm/types.h>

#include <asm/types.h>

#include <linux/ioctl.h>

#include <linux/ioctl.h>





#define KVM_API_VERSION 10

#define KVM_API_VERSION 11





/*

/*

 * Architectural interrupt line count, and the size of the bitmap needed

 * Architectural interrupt line count, and the size of the bitmap needed
@@ -58,9 +58,8 @@ enum kvm_exit_reason { 
/* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */

/* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */

struct kvm_run {

struct kvm_run {

	/* in */

	/* in */

	__u32 io_completed; /* mmio/pio request completed */

	__u8 request_interrupt_window;

	__u8 request_interrupt_window;

	__u8 padding1[3];

	__u8 padding1[7];





	/* out */

	/* out */

	__u32 exit_reason;

	__u32 exit_reason;