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Commit b4e63f56 authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: Allow userspace to process hypercalls which have no kernel handler 



This is useful for paravirtualized graphics devices, for example.

Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent 5d308f45

drivers/kvm/kvm_main.c

+17 −1
Original line number Original line Diff line number Diff line
@@ -1203,7 +1203,16 @@ int kvm_hypercall(struct kvm_vcpu *vcpu, struct kvm_run *run) 
	}

	}

	switch (nr) {

	switch (nr) {

	default:

	default:

		;

		run->hypercall.args[0] = a0;

		run->hypercall.args[1] = a1;

		run->hypercall.args[2] = a2;

		run->hypercall.args[3] = a3;

		run->hypercall.args[4] = a4;

		run->hypercall.args[5] = a5;

		run->hypercall.ret = ret;

		run->hypercall.longmode = is_long_mode(vcpu);

		kvm_arch_ops->decache_regs(vcpu);

		return 0;

	}

	}

	vcpu->regs[VCPU_REGS_RAX] = ret;

	vcpu->regs[VCPU_REGS_RAX] = ret;

	kvm_arch_ops->decache_regs(vcpu);

	kvm_arch_ops->decache_regs(vcpu);
@@ -1599,6 +1608,13 @@ static int kvm_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 




	vcpu->mmio_needed = 0;

	vcpu->mmio_needed = 0;





	if (kvm_run->exit_type == KVM_EXIT_TYPE_VM_EXIT

	    && kvm_run->exit_reason == KVM_EXIT_HYPERCALL) {

		kvm_arch_ops->cache_regs(vcpu);

		vcpu->regs[VCPU_REGS_RAX] = kvm_run->hypercall.ret;

		kvm_arch_ops->decache_regs(vcpu);

	}



	r = kvm_arch_ops->run(vcpu, kvm_run);

	r = kvm_arch_ops->run(vcpu, kvm_run);





	vcpu_put(vcpu);

	vcpu_put(vcpu);

include/linux/kvm.h

+9 −1
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 6

#define KVM_API_VERSION 7





/*

/*

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

 * Architectural interrupt line count, and the size of the bitmap needed
@@ -41,6 +41,7 @@ enum kvm_exit_reason { 
	KVM_EXIT_UNKNOWN          = 0,

	KVM_EXIT_UNKNOWN          = 0,

	KVM_EXIT_EXCEPTION        = 1,

	KVM_EXIT_EXCEPTION        = 1,

	KVM_EXIT_IO               = 2,

	KVM_EXIT_IO               = 2,

	KVM_EXIT_HYPERCALL        = 3,

	KVM_EXIT_DEBUG            = 4,

	KVM_EXIT_DEBUG            = 4,

	KVM_EXIT_HLT              = 5,

	KVM_EXIT_HLT              = 5,

	KVM_EXIT_MMIO             = 6,

	KVM_EXIT_MMIO             = 6,
@@ -103,6 +104,13 @@ struct kvm_run { 
			__u32 len;

			__u32 len;

			__u8  is_write;

			__u8  is_write;

		} mmio;

		} mmio;

		/* KVM_EXIT_HYPERCALL */

		struct {

			__u64 args[6];

			__u64 ret;

			__u32 longmode;

			__u32 pad;

		} hypercall;

	};

	};

};

};