Commit 13ffb97a authored by Joao Martins's avatar Joao Martins Committed by David Woodhouse
Browse files

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: default avatarJoao Martins <joao.m.martins@oracle.com>
Signed-off-by: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
parent 1ea9f2ed

arch/x86/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -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 {

arch/x86/kvm/xen.c

+36 −4
Original line number Diff line number Diff line
@@ -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;



	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;

	}

include/uapi/linux/kvm.h

+4 −0
Original line number Diff line number Diff line
@@ -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 {