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

Roy Hopkins posted 17 patches 4 months, 3 weeks ago
Maintainers: "Philippe Mathieu-Daudé" <philmd@linaro.org>, "Daniel P. Berrangé" <berrange@redhat.com>, Kashyap Chamarthy <kchamart@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Eduardo Habkost <eduardo@habkost.net>, "Michael S. Tsirkin" <mst@redhat.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, Thomas Huth <thuth@redhat.com>, Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>
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[PATCH v4 02/17] backends/confidential-guest-support: Add functions to support IGVM
Posted by Roy Hopkins 4 months, 3 weeks ago
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)
+
 #endif /* !CONFIG_USER_ONLY */
 
 #endif /* QEMU_CONFIDENTIAL_GUEST_SUPPORT_H */
diff --git a/backends/confidential-guest-support.c b/backends/confidential-guest-support.c
index 052fde8db0..68e6fd9d18 100644
--- a/backends/confidential-guest-support.c
+++ b/backends/confidential-guest-support.c
@@ -14,14 +14,45 @@
 #include "qemu/osdep.h"
 
 #include "exec/confidential-guest-support.h"
+#include "qapi/error.h"
 
 OBJECT_DEFINE_ABSTRACT_TYPE(ConfidentialGuestSupport,
                             confidential_guest_support,
                             CONFIDENTIAL_GUEST_SUPPORT,
                             OBJECT)
 
+static int check_support(ConfidentialGuestPlatformType platform,
+                         uint16_t platform_version, uint8_t highest_vtl,
+                         uint64_t shared_gpa_boundary)
+{
+    /* Default: no support. */
+    return 0;
+}
+
+static int set_guest_state(hwaddr gpa, uint8_t *ptr, uint64_t len,
+                           ConfidentialGuestPageType memory_type,
+                           uint16_t cpu_index, Error **errp)
+{
+    error_setg(errp,
+               "Setting confidential guest state is not supported for this platform");
+    return -1;
+}
+
+static int get_mem_map_entry(int index, ConfidentialGuestMemoryMapEntry *entry,
+                             Error **errp)
+{
+    error_setg(
+        errp,
+        "Obtaining the confidential guest memory map is not supported for this platform");
+    return -1;
+}
+
 static void confidential_guest_support_class_init(ObjectClass *oc, void *data)
 {
+    ConfidentialGuestSupportClass *cgsc = CONFIDENTIAL_GUEST_SUPPORT_CLASS(oc);
+    cgsc->check_support = check_support;
+    cgsc->set_guest_state = set_guest_state;
+    cgsc->get_mem_map_entry = get_mem_map_entry;
 }
 
 static void confidential_guest_support_init(Object *obj)
-- 
2.43.0
Re: [PATCH v4 02/17] backends/confidential-guest-support: Add functions to support IGVM
Posted by Daniel P. Berrangé 4 months ago
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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