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

[Roy Hopkins]

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