Re: [PATCH v5 00/34] SEV-ES hypervisor support

[Paolo Bonzini]

On 15/12/20 17:46, Tom Lendacky wrote:
> KVM: SVM: Add AP_JUMP_TABLE support in prep for AP booting

Great, thanks!

Paolo

> From: Tom Lendacky<thomas.lendacky@xxxxxxx>
>
> The GHCB specification requires the hypervisor to save the address of an
> AP Jump Table so that, for example, vCPUs that have been parked by UEFI
> can be started by the OS. Provide support for the AP Jump Table set/get
> exit code.
>
> Signed-off-by: Tom Lendacky<thomas.lendacky@xxxxxxx>
> ---
>   arch/x86/kvm/svm/sev.c |   28 ++++++++++++++++++++++++++++
>   arch/x86/kvm/svm/svm.h |    1 +
>   2 files changed, 29 insertions(+)
>
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index 6eb097714d43..8b5ef0fe4490 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -18,6 +18,8 @@
>   #include <linux/trace_events.h>
>   #include <asm/fpu/internal.h>
>   
> +#include <asm/trapnr.h>
> +
>   #include "x86.h"
>   #include "svm.h"
>   #include "cpuid.h"
> @@ -1559,6 +1561,7 @@ static int sev_es_validate_vmgexit(struct vcpu_svm *svm)
>   			goto vmgexit_err;
>   		break;
>   	case SVM_VMGEXIT_NMI_COMPLETE:
> +	case SVM_VMGEXIT_AP_JUMP_TABLE:
>   	case SVM_VMGEXIT_UNSUPPORTED_EVENT:
>   		break;
>   	default:
> @@ -1883,6 +1886,31 @@ int sev_handle_vmgexit(struct vcpu_svm *svm)
>   	case SVM_VMGEXIT_NMI_COMPLETE:
>   		ret = svm_invoke_exit_handler(svm, SVM_EXIT_IRET);
>   		break;
> +	case SVM_VMGEXIT_AP_JUMP_TABLE: {
> +		struct kvm_sev_info *sev = &to_kvm_svm(svm->vcpu.kvm)->sev_info;
> +
> +		switch (control->exit_info_1) {
> +		case 0:
> +			/* Set AP jump table address */
> +			sev->ap_jump_table = control->exit_info_2;
> +			break;
> +		case 1:
> +			/* Get AP jump table address */
> +			ghcb_set_sw_exit_info_2(ghcb, sev->ap_jump_table);
> +			break;
> +		default:
> +			pr_err("svm: vmgexit: unsupported AP jump table request - exit_info_1=%#llx\n",
> +			       control->exit_info_1);
> +			ghcb_set_sw_exit_info_1(ghcb, 1);
> +			ghcb_set_sw_exit_info_2(ghcb,
> +						X86_TRAP_UD |
> +						SVM_EVTINJ_TYPE_EXEPT |
> +						SVM_EVTINJ_VALID);
> +		}
> +
> +		ret = 1;
> +		break;
> +	}
>   	case SVM_VMGEXIT_UNSUPPORTED_EVENT:
>   		vcpu_unimpl(&svm->vcpu,
>   			    "vmgexit: unsupported event - exit_info_1=%#llx, exit_info_2=%#llx\n",
> diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
> index a5067f776ce0..5431e6335e2e 100644
> --- a/arch/x86/kvm/svm/svm.h
> +++ b/arch/x86/kvm/svm/svm.h
> @@ -78,6 +78,7 @@ struct kvm_sev_info {
>   	int fd;			/* SEV device fd */
>   	unsigned long pages_locked; /* Number of pages locked */
>   	struct list_head regions_list;  /* List of registered regions */
> +	u64 ap_jump_table;	/* SEV-ES AP Jump Table address */
>   };
>   
>   struct kvm_svm {