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>
---
arch/x86/include/asm/kvm_host.h | 3 +++
arch/x86/kvm/x86.c | 21 +++++++++++++++
arch/x86/kvm/xen.c | 60 +++++++++++++++++++++++++++++++++++++++++
arch/x86/kvm/xen.h | 4 +++
include/uapi/linux/kvm.h | 15 +++++++++++
5 files changed, 103 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 0f469ce439c0..befc0e37f162 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -843,6 +843,9 @@ struct kvm_hv {
/* Xen emulation context */
struct kvm_xen {
u64 xen_hypercall;
+
+ gfn_t shinfo_addr;
+ struct shared_info *shinfo;
};
enum kvm_irqchip_mode {
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index be8def385e3f..1eda96304180 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4793,6 +4793,26 @@ long kvm_arch_vm_ioctl(struct file *filp,
r = 0;
break;
}
+ case KVM_XEN_HVM_GET_ATTR: {
+ struct kvm_xen_hvm_attr xha;
+
+ r = -EFAULT;
+ if (copy_from_user(&xha, argp, sizeof(xha)))
+ goto out;
+ r = kvm_xen_hvm_get_attr(kvm, &xha);
+ if (copy_to_user(argp, &xha, sizeof(xha)))
+ goto out;
+ break;
+ }
+ case KVM_XEN_HVM_SET_ATTR: {
+ struct kvm_xen_hvm_attr xha;
+
+ r = -EFAULT;
+ if (copy_from_user(&xha, argp, sizeof(xha)))
+ goto out;
+ r = kvm_xen_hvm_set_attr(kvm, &xha);
+ break;
+ }
case KVM_SET_CLOCK: {
struct kvm_clock_data user_ns;
u64 now_ns;
@@ -9279,6 +9299,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
kvm_mmu_uninit_vm(kvm);
kvm_page_track_cleanup(kvm);
kvm_hv_destroy_vm(kvm);
+ kvm_xen_destroy_vm(kvm);
}
void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 76f0e4b812d2..4df223bd3cd7 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -11,9 +11,61 @@
#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)
+{
+ struct shared_info *shared_info;
+ struct page *page;
+
+ page = gfn_to_page(kvm, gfn);
+ if (is_error_page(page))
+ return -EINVAL;
+
+ kvm->arch.xen.shinfo_addr = gfn;
+
+ shared_info = page_to_virt(page);
+ memset(shared_info, 0, sizeof(struct shared_info));
+ kvm->arch.xen.shinfo = shared_info;
+ return 0;
+}
+
+int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
+{
+ int r = -ENOENT;
+
+ switch (data->type) {
+ case KVM_XEN_ATTR_TYPE_SHARED_INFO: {
+ gfn_t gfn = data->u.shared_info.gfn;
+
+ r = kvm_xen_shared_info_init(kvm, gfn);
+ break;
+ }
+ default:
+ break;
+ }
+
+ return r;
+}
+
+int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
+{
+ int r = -ENOENT;
+
+ switch (data->type) {
+ case KVM_XEN_ATTR_TYPE_SHARED_INFO: {
+ data->u.shared_info.gfn = kvm->arch.xen.shinfo_addr;
+ break;
+ }
+ default:
+ break;
+ }
+
+ return r;
+}
+
bool kvm_xen_hypercall_enabled(struct kvm *kvm)
{
return READ_ONCE(kvm->arch.xen.xen_hypercall);
@@ -77,3 +129,11 @@ int kvm_xen_hypercall(struct kvm_vcpu *vcpu)
return 0;
}
+
+void kvm_xen_destroy_vm(struct kvm *kvm)
+{
+ struct kvm_xen *xen = &kvm->arch.xen;
+
+ if (xen->shinfo)
+ put_page(virt_to_page(xen->shinfo));
+}
diff --git a/arch/x86/kvm/xen.h b/arch/x86/kvm/xen.h
index a2ae079c3ef3..bb38edf383fe 100644
--- a/arch/x86/kvm/xen.h
+++ b/arch/x86/kvm/xen.h
@@ -3,8 +3,12 @@
#ifndef __ARCH_X86_KVM_XEN_H__
#define __ARCH_X86_KVM_XEN_H__
+int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data);
+int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data);
bool kvm_xen_hypercall_enabled(struct kvm *kvm);
bool kvm_xen_hypercall_set(struct kvm *kvm);
int kvm_xen_hypercall(struct kvm_vcpu *vcpu);
+void kvm_xen_destroy_vm(struct kvm *kvm);
+
#endif
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index d07520c216a1..de2168d235af 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1455,6 +1455,21 @@ struct kvm_enc_region {
/* Available with KVM_CAP_HYPERV_CPUID */
#define KVM_GET_SUPPORTED_HV_CPUID _IOWR(KVMIO, 0xc1, struct kvm_cpuid2)
+#define KVM_XEN_HVM_GET_ATTR _IOWR(KVMIO, 0xc2, struct kvm_xen_hvm_attr)
+#define KVM_XEN_HVM_SET_ATTR _IOW(KVMIO, 0xc3, struct kvm_xen_hvm_attr)
+
+struct kvm_xen_hvm_attr {
+ __u16 type;
+
+ union {
+ struct {
+ __u64 gfn;
+ } shared_info;
+ } u;
+};
+
+#define KVM_XEN_ATTR_TYPE_SHARED_INFO 0x0
+
/* Secure Encrypted Virtualization command */
enum sev_cmd_id {
/* Guest initialization commands */
--
2.11.0
