From: Joao Martins <joao.m.martins@xxxxxxxxxx>
We add a new ioctl, XEN_HVM_SHARED_INFO, to allow hypervisor
to know where the guest's shared info page is.
Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/xen.c | 27 +++++++++++++++++++++++++++
include/uapi/linux/kvm.h | 4 ++++
3 files changed, 33 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4ca6e060b578..07ae5887afa1 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -897,6 +897,8 @@ struct msr_bitmap_range {
/* Xen emulation context */
struct kvm_xen {
bool long_mode;
+ bool shinfo_set;
+ struct gfn_to_hva_cache shinfo_cache;
};
enum kvm_irqchip_mode {
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 52cb9e465542..9dd9c42842b8 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -13,9 +13,23 @@
#include <linux/kvm_host.h>
#include <trace/events/kvm.h>
+#include <xen/interface/xen.h>
#include "trace.h"
+static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn)
+{
+ int ret;
+
+ ret = kvm_gfn_to_hva_cache_init(kvm, &kvm->arch.xen.shinfo_cache,
+ gfn_to_gpa(gfn), PAGE_SIZE);
+ if (ret)
+ return ret;
+
+ kvm->arch.xen.shinfo_set = true;
+ return 0;
+}
+
int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
{
int r = -ENOENT;
@@ -28,6 +42,11 @@ int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
kvm->arch.xen.long_mode = !!data->u.long_mode;
r = 0;
break;
+
+ case KVM_XEN_ATTR_TYPE_SHARED_INFO:
+ r = kvm_xen_shared_info_init(kvm, data->u.shared_info.gfn);
+ break;
+
default:
break;
}
@@ -44,6 +63,14 @@ int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
data->u.long_mode = kvm->arch.xen.long_mode;
r = 0;
break;
+
+ case KVM_XEN_ATTR_TYPE_SHARED_INFO:
+ if (kvm->arch.xen.shinfo_set) {
+ data->u.shared_info.gfn = gpa_to_gfn(kvm->arch.xen.shinfo_cache.gpa);
+ r = 0;
+ }
+ break;
+
default:
break;
}
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 3293866d5ee1..0c04bb6eda09 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1593,11 +1593,15 @@ struct kvm_xen_hvm_attr {
__u16 pad[3];
union {
__u8 long_mode;
+ struct {
+ __u64 gfn;
+ } shared_info;
__u64 pad[4];
} u;
};
#define KVM_XEN_ATTR_TYPE_LONG_MODE 0x0
+#define KVM_XEN_ATTR_TYPE_SHARED_INFO 0x1
/* Secure Encrypted Virtualization command */
enum sev_cmd_id {
--
2.29.2
