Commit c24a950e authored by Peter Gonda's avatar Peter Gonda Committed by Paolo Bonzini
Browse files

KVM, SEV: Add KVM_EXIT_SHUTDOWN metadata for SEV-ES 



If an SEV-ES guest requests termination, exit to userspace with
KVM_EXIT_SYSTEM_EVENT and a dedicated SEV_TERM type instead of -EINVAL
so that userspace can take appropriate action.

See AMD's GHCB spec section '4.1.13 Termination Request' for more details.

Suggested-by: default avatarSean Christopherson <seanjc@google.com>
Suggested-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: default avatarPeter Gonda <pgonda@google.com>

Reported-by: default avatarkernel test robot <lkp@intel.com>
Message-Id: <20220407210233.782250-1-pgonda@google.com>
[Add documentatino. - Paolo]
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 9bd1f0ef

Documentation/virt/kvm/api.rst

+11 −1
Original line number Diff line number Diff line
@@ -6088,8 +6088,12 @@ should put the acknowledged interrupt vector into the 'epr' field. 
  #define KVM_SYSTEM_EVENT_SHUTDOWN       1

  #define KVM_SYSTEM_EVENT_RESET          2

  #define KVM_SYSTEM_EVENT_CRASH          3

  #define KVM_SYSTEM_EVENT_SEV_TERM       4

  #define KVM_SYSTEM_EVENT_NDATA_VALID    (1u << 31)

			__u32 type;

                        __u32 ndata;

			__u64 flags;

                        __u64 data[16];

		} system_event;



If exit_reason is KVM_EXIT_SYSTEM_EVENT then the vcpu has triggered
@@ -6099,7 +6103,7 @@ HVC instruction based PSCI call from the vcpu. The 'type' field describes 
the system-level event type. The 'flags' field describes architecture

specific flags for the system-level event.



Valid values for 'type' are:

Valid values for bits 30:0 of 'type' are:



 - KVM_SYSTEM_EVENT_SHUTDOWN -- the guest has requested a shutdown of the

   VM. Userspace is not obliged to honour this, and if it does honour
@@ -6112,12 +6116,18 @@ Valid values for 'type' are: 
   has requested a crash condition maintenance. Userspace can choose

   to ignore the request, or to gather VM memory core dump and/or

   reset/shutdown of the VM.

 - KVM_SYSTEM_EVENT_SEV_TERM -- an AMD SEV guest requested termination.

   The guest physical address of the guest's GHCB is stored in `data[0]`.



Valid flags are:



 - KVM_SYSTEM_EVENT_RESET_FLAG_PSCI_RESET2 (arm64 only) -- the guest issued

   a SYSTEM_RESET2 call according to v1.1 of the PSCI specification.



Extra data for this event is stored in the `data[]` array, up to index

`ndata-1` included, if bit 31 is set in `type`.  The data depends on the

`type` field.  There is no extra data if bit 31 is clear or `ndata` is zero.



::



		/* KVM_EXIT_IOAPIC_EOI */

arch/x86/kvm/svm/sev.c

+7 −2
Original line number Diff line number Diff line
@@ -2738,8 +2738,13 @@ static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm) 
		pr_info("SEV-ES guest requested termination: %#llx:%#llx\n",

			reason_set, reason_code);



		ret = -EINVAL;

		break;

		vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;

		vcpu->run->system_event.type = KVM_SYSTEM_EVENT_SEV_TERM |

					       KVM_SYSTEM_EVENT_NDATA_VALID;

		vcpu->run->system_event.ndata = 1;

		vcpu->run->system_event.data[1] = control->ghcb_gpa;



		return 0;

	}

	default:

		/* Error, keep GHCB MSR value as-is */

include/uapi/linux/kvm.h

+4 −1
Original line number Diff line number Diff line
@@ -444,8 +444,11 @@ struct kvm_run { 
#define KVM_SYSTEM_EVENT_SHUTDOWN       1

#define KVM_SYSTEM_EVENT_RESET          2

#define KVM_SYSTEM_EVENT_CRASH          3

#define KVM_SYSTEM_EVENT_SEV_TERM       4

#define KVM_SYSTEM_EVENT_NDATA_VALID    (1u << 31)

			__u32 type;

			__u64 flags;

			__u32 ndata;

			__u64 data[16];

		} system_event;

		/* KVM_EXIT_S390_STSI */

		struct {