Re: [PATCH 01/10] KVM: SEV: fix compat ABI for KVM_MEMORY_ENCRYPT_OP

[Michael Roth <michael.roth@amd.com>]

On Fri, Feb 09, 2024 at 01:37:33PM -0500, Paolo Bonzini wrote:
> The data structs for KVM_MEMORY_ENCRYPT_OP have different sizes for 32- and 64-bit
> kernels, but they do not make any attempt to convert from one ABI to the other.
> Fix this by adding the appropriate padding.
> 
> No functional change intended for 64-bit userspace.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Michael Roth <michael.roth@amd.com>

> ---
>  arch/x86/include/uapi/asm/kvm.h | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
> index 0ad6bda1fc39..b305daff056e 100644
> --- a/arch/x86/include/uapi/asm/kvm.h
> +++ b/arch/x86/include/uapi/asm/kvm.h
> @@ -687,6 +687,7 @@ enum sev_cmd_id {
>  
>  struct kvm_sev_cmd {
>  	__u32 id;
> +	__u32 pad0;
>  	__u64 data;
>  	__u32 error;
>  	__u32 sev_fd;
> @@ -697,28 +698,35 @@ struct kvm_sev_launch_start {
>  	__u32 policy;
>  	__u64 dh_uaddr;
>  	__u32 dh_len;
> +	__u32 pad0;
>  	__u64 session_uaddr;
>  	__u32 session_len;
> +	__u32 pad1;
>  };
>  
>  struct kvm_sev_launch_update_data {
>  	__u64 uaddr;
>  	__u32 len;
> +	__u32 pad0;
>  };
>  
>  
>  struct kvm_sev_launch_secret {
>  	__u64 hdr_uaddr;
>  	__u32 hdr_len;
> +	__u32 pad0;
>  	__u64 guest_uaddr;
>  	__u32 guest_len;
> +	__u32 pad1;
>  	__u64 trans_uaddr;
>  	__u32 trans_len;
> +	__u32 pad2;
>  };
>  
>  struct kvm_sev_launch_measure {
>  	__u64 uaddr;
>  	__u32 len;
> +	__u32 pad0;
>  };
>  
>  struct kvm_sev_guest_status {
> @@ -731,33 +739,43 @@ struct kvm_sev_dbg {
>  	__u64 src_uaddr;
>  	__u64 dst_uaddr;
>  	__u32 len;
> +	__u32 pad0;
>  };
>  
>  struct kvm_sev_attestation_report {
>  	__u8 mnonce[16];
>  	__u64 uaddr;
>  	__u32 len;
> +	__u32 pad0;
>  };
>  
>  struct kvm_sev_send_start {
>  	__u32 policy;
> +	__u32 pad0;
>  	__u64 pdh_cert_uaddr;
>  	__u32 pdh_cert_len;
> +	__u32 pad1;
>  	__u64 plat_certs_uaddr;
>  	__u32 plat_certs_len;
> +	__u32 pad2;
>  	__u64 amd_certs_uaddr;
>  	__u32 amd_certs_len;
> +	__u32 pad3;
>  	__u64 session_uaddr;
>  	__u32 session_len;
> +	__u32 pad4;
>  };
>  
>  struct kvm_sev_send_update_data {
>  	__u64 hdr_uaddr;
>  	__u32 hdr_len;
> +	__u32 pad0;
>  	__u64 guest_uaddr;
>  	__u32 guest_len;
> +	__u32 pad1;
>  	__u64 trans_uaddr;
>  	__u32 trans_len;
> +	__u32 pad2;
>  };
>  
>  struct kvm_sev_receive_start {
> @@ -765,17 +783,22 @@ struct kvm_sev_receive_start {
>  	__u32 policy;
>  	__u64 pdh_uaddr;
>  	__u32 pdh_len;
> +	__u32 pad0;
>  	__u64 session_uaddr;
>  	__u32 session_len;
> +	__u32 pad1;
>  };
>  
>  struct kvm_sev_receive_update_data {
>  	__u64 hdr_uaddr;
>  	__u32 hdr_len;
> +	__u32 pad0;
>  	__u64 guest_uaddr;
>  	__u32 guest_len;
> +	__u32 pad1;
>  	__u64 trans_uaddr;
>  	__u32 trans_len;
> +	__u32 pad2;
>  };
>  
>  #define KVM_X2APIC_API_USE_32BIT_IDS            (1ULL << 0)
> -- 
> 2.39.0
> 
>