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authorJoao Martins <joao.m.martins@oracle.com>2018-06-15 21:17:14 -0400
committerDavid Woodhouse <dwmw@amazon.co.uk>2021-02-04 14:19:38 +0000
commit13ffb97a3b11998450d51457b6b3617781953f7c (patch)
tree9a0f9c256b9e3474a1396eec41c0d5a6045ac0e8
parent1ea9f2ed81c4b058a3dc73b75d684a1f451ce714 (diff)
KVM: x86/xen: register shared_info page
Add KVM_XEN_ATTR_TYPE_SHARED_INFO to allow hypervisor to know where the guest's shared info page is. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
-rw-r--r--arch/x86/include/asm/kvm_host.h2
-rw-r--r--arch/x86/kvm/xen.c40
-rw-r--r--include/uapi/linux/kvm.h4
3 files changed, 42 insertions, 4 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 016a005cc2ad..00d1233cfd55 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -908,6 +908,8 @@ 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 55da739267b1..924d4e853108 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -13,25 +13,49 @@
#include <linux/kvm_host.h>
#include <trace/events/kvm.h>
+#include <xen/interface/xen.h>
#include "trace.h"
DEFINE_STATIC_KEY_DEFERRED_FALSE(kvm_xen_enabled, HZ);
+static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn)
+{
+ int ret;
+ int idx = srcu_read_lock(&kvm->srcu);
+
+ ret = kvm_gfn_to_hva_cache_init(kvm, &kvm->arch.xen.shinfo_cache,
+ gfn_to_gpa(gfn), PAGE_SIZE);
+ if (!ret) {
+ kvm->arch.xen.shinfo_set = true;
+ }
+
+ srcu_read_unlock(&kvm->srcu, idx);
+ return ret;
+}
+
int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
{
int r = -ENOENT;
+ mutex_lock(&kvm->lock);
+
mutex_unlock(&kvm->lock);
switch (data->type) {
case KVM_XEN_ATTR_TYPE_LONG_MODE:
- if (!IS_ENABLED(CONFIG_64BIT) && data->u.long_mode)
- return -EINVAL;
+ if (!IS_ENABLED(CONFIG_64BIT) && data->u.long_mode) {
+ r = -EINVAL;
+ } else {
+ kvm->arch.xen.long_mode = !!data->u.long_mode;
+ r = 0;
+ }
+ break;
- kvm->arch.xen.long_mode = !!data->u.long_mode;
- r = 0;
+ case KVM_XEN_ATTR_TYPE_SHARED_INFO:
+ r = kvm_xen_shared_info_init(kvm, data->u.shared_info.gfn);
break;
+
default:
break;
}
@@ -51,6 +75,14 @@ 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 11644954a2e2..f57f6e741a28 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1595,11 +1595,15 @@ struct kvm_xen_hvm_attr {
__u16 pad[3];
union {
__u8 long_mode;
+ struct {
+ __u64 gfn;
+ } shared_info;
__u64 pad[8];
} 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 {