[patch 1/3] KVM: x86: add ioctls to get/set PIO state

Marcelo Tosatti
2010-01-28T19:06:49Z

[-- Attachment #1: kernel-get-set-pio --]
[-- Type: text/plain, Size: 3748 bytes --]

A vcpu can be stopped after handling IO in userspace,
but before returning to kernel to finish processing.

Add ioctls to get/set the PIO state.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/arch/x86/include/asm/kvm.h b/arch/x86/include/asm/kvm.h
index f46b79f..c1b2b8c 100644
--- a/arch/x86/include/asm/kvm.h
+++ b/arch/x86/include/asm/kvm.h
@@ -284,4 +284,18 @@ struct kvm_vcpu_events {
__u32 reserved[10];
};

+struct kvm_pio_request {
+ __u64 guest_gva;
+ __u32 count;
+ __u32 cur_count;
+ __u16 port;
+ __u8 size;
+ __u8 in;
+ __u8 string;
+ __u8 down;
+ __u8 rep;
+ __u8 pad;
+};
+
+
#endif /* _ASM_X86_KVM_H */
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 1522337..28f31e1 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -222,18 +222,6 @@ struct kvm_pv_mmu_op_buffer {
char buf[512] __aligned(sizeof(long));
};

-struct kvm_pio_request {
- unsigned long count;
- int cur_count;
- gva_t guest_gva;
- int in;
- int port;
- int size;
- int string;
- int down;
- int rep;
-};
-
/*
* x86 supports 3 paging modes (4-level 64-bit, 3-level 64-bit, and 2-level
* 32-bit). The kvm_mmu structure abstracts the details of the current mmu
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ac8672f..99d991a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1575,6 +1575,9 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_COALESCED_MMIO:
r = KVM_COALESCED_MMIO_PAGE_OFFSET;
break;
+ case KVM_CAP_PIO:
+ r = KVM_PIO_PAGE_OFFSET;
+ break;
case KVM_CAP_VAPIC:
r = !kvm_x86_ops->cpu_has_accelerated_tpr();
break;
@@ -2175,6 +2178,26 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
return 0;
}

+static void kvm_vcpu_ioctl_x86_get_pio(struct kvm_vcpu *vcpu,
+ struct kvm_pio_request *pio)
+{
+ vcpu_load(vcpu);
+ memcpy(pio, &vcpu->arch.pio, sizeof(struct kvm_pio_request));
+ vcpu_put(vcpu);
+}
+
+static int kvm_vcpu_ioctl_x86_set_pio(struct kvm_vcpu *vcpu,
+ struct kvm_pio_request *pio)
+{
+ if (!pio->string && pio->size > 4)
+ return -EINVAL;
+
+ vcpu_load(vcpu);
+ memcpy(&vcpu->arch.pio, pio, sizeof(struct kvm_pio_request));
+ vcpu_put(vcpu);
+ return 0;
+}
+
long kvm_arch_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
@@ -2353,6 +2376,27 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
r = kvm_vcpu_ioctl_x86_set_vcpu_events(vcpu, &events);
break;
}
+ case KVM_SET_VCPU_PIO: {
+ struct kvm_pio_request pio;
+
+ r = -EFAULT;
+ if (copy_from_user(&pio, argp, sizeof(struct kvm_pio_request)))
+ break;
+
+ r = kvm_vcpu_ioctl_x86_set_pio(vcpu, &pio);
+ break;
+ }
+ case KVM_GET_VCPU_PIO: {
+ struct kvm_pio_request pio;
+
+ kvm_vcpu_ioctl_x86_get_pio(vcpu, &pio);
+
+ r = -EFAULT;
+ if (copy_to_user(argp, &pio, sizeof(struct kvm_pio_request)))
+ break;
+ r = 0;
+ break;
+ }
default:
r = -EINVAL;
}
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 4c4937e..0b56d41 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -500,6 +500,7 @@ struct kvm_ioeventfd {
#define KVM_CAP_HYPERV 44
#define KVM_CAP_HYPERV_VAPIC 45
#define KVM_CAP_HYPERV_SPIN 46
+#define KVM_CAP_PIO 47

#ifdef KVM_CAP_IRQ_ROUTING

@@ -686,6 +687,8 @@ struct kvm_clock_data {
/* Available with KVM_CAP_VCPU_EVENTS */
#define KVM_GET_VCPU_EVENTS _IOR(KVMIO, 0x9f, struct kvm_vcpu_events)
#define KVM_SET_VCPU_EVENTS _IOW(KVMIO, 0xa0, struct kvm_vcpu_events)
+#define KVM_GET_VCPU_PIO _IOR(KVMIO, 0xa1, struct kvm_pio_request)
+#define KVM_SET_VCPU_PIO _IOW(KVMIO, 0xa2, struct kvm_pio_request)

#define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0)