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-rw-r--r--Documentation/virt/kvm/api.rst25
-rw-r--r--arch/x86/include/uapi/asm/kvm.h6
-rw-r--r--arch/x86/kvm/xen.c40
3 files changed, 56 insertions, 15 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 3ec0b7a455a0..3372be85b335 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -372,7 +372,7 @@ The bits in the dirty bitmap are cleared before the ioctl returns, unless
KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is enabled. For more information,
see the description of the capability.
-Note that the Xen shared info page, if configured, shall always be assumed
+Note that the Xen shared_info page, if configured, shall always be assumed
to be dirty. KVM will not explicitly mark it such.
@@ -5487,8 +5487,9 @@ KVM_PV_ASYNC_CLEANUP_PERFORM
__u8 long_mode;
__u8 vector;
__u8 runstate_update_flag;
- struct {
+ union {
__u64 gfn;
+ __u64 hva;
} shared_info;
struct {
__u32 send_port;
@@ -5516,10 +5517,10 @@ type values:
KVM_XEN_ATTR_TYPE_LONG_MODE
Sets the ABI mode of the VM to 32-bit or 64-bit (long mode). This
- determines the layout of the shared info pages exposed to the VM.
+ determines the layout of the shared_info page exposed to the VM.
KVM_XEN_ATTR_TYPE_SHARED_INFO
- Sets the guest physical frame number at which the Xen "shared info"
+ Sets the guest physical frame number at which the Xen shared_info
page resides. Note that although Xen places vcpu_info for the first
32 vCPUs in the shared_info page, KVM does not automatically do so
and instead requires that KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO be used
@@ -5528,7 +5529,7 @@ KVM_XEN_ATTR_TYPE_SHARED_INFO
not be aware of the Xen CPU id which is used as the index into the
vcpu_info[] array, so may know the correct default location.
- Note that the shared info page may be constantly written to by KVM;
+ Note that the shared_info page may be constantly written to by KVM;
it contains the event channel bitmap used to deliver interrupts to
a Xen guest, amongst other things. It is exempt from dirty tracking
mechanisms — KVM will not explicitly mark the page as dirty each
@@ -5537,9 +5538,21 @@ KVM_XEN_ATTR_TYPE_SHARED_INFO
any vCPU has been running or any event channel interrupts can be
routed to the guest.
- Setting the gfn to KVM_XEN_INVALID_GFN will disable the shared info
+ Setting the gfn to KVM_XEN_INVALID_GFN will disable the shared_info
page.
+KVM_XEN_ATTR_TYPE_SHARED_INFO_HVA
+ If the KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA flag is also set in the
+ Xen capabilities, then this attribute may be used to set the
+ userspace address at which the shared_info page resides, which
+ will always be fixed in the VMM regardless of where it is mapped
+ in guest physical address space. This attribute should be used in
+ preference to KVM_XEN_ATTR_TYPE_SHARED_INFO as it avoids
+ unnecessary invalidation of an internal cache when the page is
+ re-mapped in guest physcial address space.
+
+ Setting the hva to zero will disable the shared_info page.
+
KVM_XEN_ATTR_TYPE_UPCALL_VECTOR
Sets the exception vector used to deliver Xen event channel upcalls.
This is the HVM-wide vector injected directly by the hypervisor
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 0ad6bda1fc39..9482f22333c8 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -549,6 +549,7 @@ struct kvm_x86_mce {
#define KVM_XEN_HVM_CONFIG_EVTCHN_SEND (1 << 5)
#define KVM_XEN_HVM_CONFIG_RUNSTATE_UPDATE_FLAG (1 << 6)
#define KVM_XEN_HVM_CONFIG_PVCLOCK_TSC_UNSTABLE (1 << 7)
+#define KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA (1 << 8)
struct kvm_xen_hvm_config {
__u32 flags;
@@ -567,9 +568,10 @@ struct kvm_xen_hvm_attr {
__u8 long_mode;
__u8 vector;
__u8 runstate_update_flag;
- struct {
+ union {
__u64 gfn;
#define KVM_XEN_INVALID_GFN ((__u64)-1)
+ __u64 hva;
} shared_info;
struct {
__u32 send_port;
@@ -611,6 +613,8 @@ struct kvm_xen_hvm_attr {
#define KVM_XEN_ATTR_TYPE_XEN_VERSION 0x4
/* Available with KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_RUNSTATE_UPDATE_FLAG */
#define KVM_XEN_ATTR_TYPE_RUNSTATE_UPDATE_FLAG 0x5
+/* Available with KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA */
+#define KVM_XEN_ATTR_TYPE_SHARED_INFO_HVA 0x6
struct kvm_xen_vcpu_attr {
__u16 type;
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 52edf676c471..45a74307cc25 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -638,20 +638,36 @@ int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
}
break;
- case KVM_XEN_ATTR_TYPE_SHARED_INFO: {
+ case KVM_XEN_ATTR_TYPE_SHARED_INFO:
+ case KVM_XEN_ATTR_TYPE_SHARED_INFO_HVA: {
int idx;
mutex_lock(&kvm->arch.xen.xen_lock);
idx = srcu_read_lock(&kvm->srcu);
- if (data->u.shared_info.gfn == KVM_XEN_INVALID_GFN) {
- kvm_gpc_deactivate(&kvm->arch.xen.shinfo_cache);
- r = 0;
+ if (data->type == KVM_XEN_ATTR_TYPE_SHARED_INFO) {
+ gfn_t gfn = data->u.shared_info.gfn;
+
+ if (gfn == KVM_XEN_INVALID_GFN) {
+ kvm_gpc_deactivate(&kvm->arch.xen.shinfo_cache);
+ r = 0;
+ } else {
+ r = kvm_gpc_activate(&kvm->arch.xen.shinfo_cache,
+ gfn_to_gpa(gfn), PAGE_SIZE);
+ }
} else {
- r = kvm_gpc_activate(&kvm->arch.xen.shinfo_cache,
- gfn_to_gpa(data->u.shared_info.gfn),
- PAGE_SIZE);
+ void __user * hva = u64_to_user_ptr(data->u.shared_info.hva);
+
+ if (!PAGE_ALIGNED(hva) || !access_ok(hva, PAGE_SIZE)) {
+ r = -EINVAL;
+ } else if (!hva) {
+ kvm_gpc_deactivate(&kvm->arch.xen.shinfo_cache);
+ r = 0;
+ } else {
+ r = kvm_gpc_activate_hva(&kvm->arch.xen.shinfo_cache,
+ (unsigned long)hva, PAGE_SIZE);
+ }
}
srcu_read_unlock(&kvm->srcu, idx);
@@ -715,13 +731,21 @@ int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
break;
case KVM_XEN_ATTR_TYPE_SHARED_INFO:
- if (kvm->arch.xen.shinfo_cache.active)
+ if (kvm_gpc_is_gpa_active(&kvm->arch.xen.shinfo_cache))
data->u.shared_info.gfn = gpa_to_gfn(kvm->arch.xen.shinfo_cache.gpa);
else
data->u.shared_info.gfn = KVM_XEN_INVALID_GFN;
r = 0;
break;
+ case KVM_XEN_ATTR_TYPE_SHARED_INFO_HVA:
+ if (kvm_gpc_is_hva_active(&kvm->arch.xen.shinfo_cache))
+ data->u.shared_info.hva = kvm->arch.xen.shinfo_cache.uhva;
+ else
+ data->u.shared_info.hva = 0;
+ r = 0;
+ break;
+
case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR:
data->u.vector = kvm->arch.xen.upcall_vector;
r = 0;
generated by cgit v1.2.3 (git 2.39.0) at 2024-09-23 06:10:43 +0300