Re: [PATCH v4 02/17] backends/confidential-guest-support: Add functions to support IGVM

["Daniel P. Berrangé" <berrange@redhat.com>]

On Wed, Jul 03, 2024 at 12:05:40PM +0100, Roy Hopkins wrote:
> In preparation for supporting the processing of IGVM files to configure
> guests, this adds a set of functions to ConfidentialGuestSupport
> allowing configuration of secure virtual machines that can be
> implemented for each supported isolation platform type such as Intel TDX
> or AMD SEV-SNP. These functions will be called by IGVM processing code
> in subsequent patches.
> 
> This commit provides a default implementation of the functions that
> either perform no action or generate an error when they are called.
> Targets that support ConfidentalGuestSupport should override these
> implementations.
> 
> Signed-off-by: Roy Hopkins <roy.hopkins@suse.com>
> ---
>  include/exec/confidential-guest-support.h | 75 +++++++++++++++++++++++
>  backends/confidential-guest-support.c     | 31 ++++++++++
>  2 files changed, 106 insertions(+)
> 
> diff --git a/include/exec/confidential-guest-support.h b/include/exec/confidential-guest-support.h
> index 02dc4e518f..4834efbe38 100644
> --- a/include/exec/confidential-guest-support.h
> +++ b/include/exec/confidential-guest-support.h
> @@ -21,6 +21,7 @@
>  #ifndef CONFIG_USER_ONLY
>  
>  #include "qom/object.h"
> +#include "exec/hwaddr.h"
>  
>  #define TYPE_CONFIDENTIAL_GUEST_SUPPORT "confidential-guest-support"
>  OBJECT_DECLARE_TYPE(ConfidentialGuestSupport,
> @@ -28,6 +29,36 @@ OBJECT_DECLARE_TYPE(ConfidentialGuestSupport,
>                      CONFIDENTIAL_GUEST_SUPPORT)
>  
>  
> +typedef enum ConfidentialGuestPlatformType {
> +    CGS_PLATFORM_SEV,
> +    CGS_PLATFORM_SEV_ES,
> +    CGS_PLATFORM_SEV_SNP,
> +} ConfidentialGuestPlatformType;
> +
> +typedef enum ConfidentialGuestMemoryType {
> +    CGS_MEM_RAM,
> +    CGS_MEM_RESERVED,
> +    CGS_MEM_ACPI,
> +    CGS_MEM_NVS,
> +    CGS_MEM_UNUSABLE,
> +} ConfidentialGuestMemoryType;
> +
> +typedef struct ConfidentialGuestMemoryMapEntry {
> +    uint64_t gpa;
> +    uint64_t size;
> +    ConfidentialGuestMemoryType type;
> +} ConfidentialGuestMemoryMapEntry;
> +
> +typedef enum ConfidentialGuestPageType {
> +    CGS_PAGE_TYPE_NORMAL,
> +    CGS_PAGE_TYPE_VMSA,
> +    CGS_PAGE_TYPE_ZERO,
> +    CGS_PAGE_TYPE_UNMEASURED,
> +    CGS_PAGE_TYPE_SECRETS,
> +    CGS_PAGE_TYPE_CPUID,
> +    CGS_PAGE_TYPE_REQUIRED_MEMORY,
> +} ConfidentialGuestPageType;
> +
>  struct ConfidentialGuestSupport {
>      Object parent;
>  
> @@ -66,6 +97,40 @@ typedef struct ConfidentialGuestSupportClass {
>  
>      int (*kvm_init)(ConfidentialGuestSupport *cgs, Error **errp);
>      int (*kvm_reset)(ConfidentialGuestSupport *cgs, Error **errp);
> +
> +    /*
> +     * Check for to see if this confidential guest supports a particular
> +     * platform or configuration
> +     */
> +    int (*check_support)(ConfidentialGuestPlatformType platform,
> +                         uint16_t platform_version, uint8_t highest_vtl,
> +                         uint64_t shared_gpa_boundary);
> +
> +    /*
> +     * Configure part of the state of a guest for a particular set of data, page
> +     * type and gpa. This can be used for example to pre-populate and measure
> +     * guest memory contents, define private ranges or set the initial CPU state
> +     * for one or more CPUs.
> +     *
> +     * If memory_type is CGS_PAGE_TYPE_VMSA then ptr points to the initial CPU
> +     * context for a virtual CPU. The format of the data depends on the type of
> +     * confidential virtual machine. For example, for SEV-ES ptr will point to a
> +     * vmcb_save_area structure that should be copied into guest memory at the
> +     * address specified in gpa. The cpu_index parameter contains the index of
> +     * the CPU the VMSA applies to.
> +     */
> +    int (*set_guest_state)(hwaddr gpa, uint8_t *ptr, uint64_t len,
> +                           ConfidentialGuestPageType memory_type,
> +                           uint16_t cpu_index, Error **errp);
> +
> +    /*
> +     * Iterate the system memory map, getting the entry with the given index
> +     * that can be populated into guest memory.
> +     *
> +     * Returns 0 for ok, 1 if the index is out of range and -1 on error.
> +     */
> +    int (*get_mem_map_entry)(int index, ConfidentialGuestMemoryMapEntry *entry,
> +                             Error **errp);
>  } ConfidentialGuestSupportClass;
>  
>  static inline int confidential_guest_kvm_init(ConfidentialGuestSupport *cgs,
> @@ -94,6 +159,16 @@ static inline int confidential_guest_kvm_reset(ConfidentialGuestSupport *cgs,
>      return 0;
>  }
>  
> +#define CONFIDENTIAL_GUEST_SUPPORT_CLASS(klass)                \
> +    OBJECT_CLASS_CHECK(ConfidentialGuestSupportClass, (klass), \
> +                       TYPE_CONFIDENTIAL_GUEST_SUPPORT)
> +#define CONFIDENTIAL_GUEST_SUPPORT(obj)           \
> +    OBJECT_CHECK(ConfidentialGuestSupport, (obj), \
> +                 TYPE_CONFIDENTIAL_GUEST_SUPPORT)
> +#define CONFIDENTIAL_GUEST_SUPPORT_GET_CLASS(obj)          \
> +    OBJECT_GET_CLASS(ConfidentialGuestSupportClass, (obj), \
> +                     TYPE_CONFIDENTIAL_GUEST_SUPPORT)

Are you sure these are needed ? Earlier in this header have

  OBJECT_DECLARE_TYPE(ConfidentialGuestSupport,
                      ConfidentialGuestSupportClass,
                      CONFIDENTIAL_GUEST_SUPPORT)

which calls DECLARE_INSTANCE_CHECKER and
DECLARE_CLASS_CHECKERS, which should define these
very same macros.


With regards,
Daniel
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