]> granicus.if.org Git - strace/blobdiff - kvm.c
tests: check decoding of vcpu auxstr
[strace] / kvm.c
diff --git a/kvm.c b/kvm.c
index 22a9e17fe5ddfcc406ff92f916ebe9347bf1fc1b..011fb4ca1c427853d8c71598f63ff5cd7cf35aea 100644 (file)
--- a/kvm.c
+++ b/kvm.c
 # include <linux/kvm.h>
 # include "print_fields.h"
 # include "arch_kvm.c"
+# include "xmalloc.h"
+# include "mmap_cache.h"
+
+struct vcpu_info {
+       struct vcpu_info *next;
+       int fd;
+       int cpuid;
+       long mmap_addr;
+       unsigned long mmap_len;
+       bool resolved;
+};
+
+static bool dump_kvm_run_structure;
+
+static struct vcpu_info *
+vcpu_find(struct tcb *const tcp, int fd)
+{
+       for (struct vcpu_info *vcpu_info = tcp->vcpu_info_list;
+            vcpu_info;
+            vcpu_info = vcpu_info->next)
+               if (vcpu_info->fd == fd)
+                       return vcpu_info;
+
+       return NULL;
+}
+
+static struct vcpu_info *
+vcpu_alloc(struct tcb *const tcp, int fd, int cpuid)
+{
+       struct vcpu_info *vcpu_info = xcalloc(1, sizeof(*vcpu_info));
+
+       vcpu_info->fd = fd;
+       vcpu_info->cpuid = cpuid;
+
+       vcpu_info->next = tcp->vcpu_info_list;
+       tcp->vcpu_info_list = vcpu_info;
+
+       return vcpu_info;
+}
+
+void
+kvm_vcpu_info_free(struct tcb *tcp)
+{
+       struct vcpu_info *head, *next;
+
+       for (head = tcp->vcpu_info_list; head; head = next) {
+               next = head->next;
+               free(head);
+       }
+
+       tcp->vcpu_info_list = NULL;
+}
+
+static void
+vcpu_register(struct tcb *const tcp, int fd, int cpuid)
+{
+       if (fd < 0)
+               return;
+
+       struct vcpu_info *vcpu_info = vcpu_find(tcp, fd);
+
+       if (!vcpu_info)
+               vcpu_info = vcpu_alloc(tcp, fd, cpuid);
+       else if (vcpu_info->cpuid != cpuid)
+       {
+               vcpu_info->cpuid = cpuid;
+               vcpu_info->resolved = false;
+       }
+}
+
+static bool
+is_map_for_file(struct mmap_cache_entry_t *map_info, void *data)
+{
+       /* major version for anon inode may be given in get_anon_bdev()
+        * in linux kernel.
+        *
+        *      *p = MKDEV(0, dev & MINORMASK);
+        *-----------------^
+        */
+       return map_info->binary_filename &&
+               map_info->major == 0 &&
+               strcmp(map_info->binary_filename, data) == 0;
+}
+
+static unsigned long
+map_len(struct mmap_cache_entry_t *map_info)
+{
+       return map_info->start_addr < map_info->end_addr
+               ? map_info->end_addr - map_info->start_addr
+               : 0;
+}
+
+#define VCPU_DENTRY_PREFIX "anon_inode:kvm-vcpu:"
+
+static struct vcpu_info*
+vcpu_get_info(struct tcb *const tcp, int fd)
+{
+       struct vcpu_info *vcpu_info = vcpu_find(tcp, fd);
+       struct mmap_cache_entry_t *map_info;
+       const char *cpuid_str;
+
+       enum mmap_cache_rebuild_result mc_stat =
+               mmap_cache_rebuild_if_invalid(tcp, __func__);
+       if (mc_stat == MMAP_CACHE_REBUILD_NOCACHE)
+               return NULL;
+
+       if (vcpu_info && vcpu_info->resolved) {
+               if (mc_stat == MMAP_CACHE_REBUILD_READY)
+                       return vcpu_info;
+               else {
+                       map_info = mmap_cache_search(tcp, vcpu_info->mmap_addr);
+                       if (map_info) {
+                               cpuid_str =
+                                       STR_STRIP_PREFIX(map_info->binary_filename,
+                                                        VCPU_DENTRY_PREFIX);
+                               if (cpuid_str != map_info->binary_filename) {
+                                       int cpuid = string_to_uint(cpuid_str);
+                                       if (cpuid < 0)
+                                               return NULL;
+                                       if (vcpu_info->cpuid == cpuid)
+                                               return vcpu_info;
+                               }
+                       }
+
+                       /* The vcpu vma may be mremap'ed. */
+                       vcpu_info->resolved = false;
+               }
+       }
+
+       /* Slow path: !vcpu_info || !vcpu_info->resolved */
+       char path[PATH_MAX + 1];
+       cpuid_str = path;
+       if (getfdpath(tcp, fd, path, sizeof(path)) >= 0)
+               cpuid_str = STR_STRIP_PREFIX(path, VCPU_DENTRY_PREFIX);
+       if (cpuid_str == path)
+               map_info = NULL;
+       else
+               map_info = mmap_cache_search_custom(tcp, is_map_for_file, path);
+
+       if (map_info) {
+               int cpuid = string_to_uint(cpuid_str);
+               if (cpuid < 0)
+                       return NULL;
+               if (!vcpu_info)
+                       vcpu_info = vcpu_alloc(tcp, fd, cpuid);
+               else if (vcpu_info->cpuid != cpuid)
+                       vcpu_info->cpuid = cpuid;
+               vcpu_info->mmap_addr = map_info->start_addr;
+               vcpu_info->mmap_len  = map_len(map_info);
+               vcpu_info->resolved  = true;
+               return vcpu_info;
+       }
+
+       return NULL;
+}
 
 static int
 kvm_ioctl_create_vcpu(struct tcb *const tcp, const kernel_ulong_t arg)
 {
        uint32_t cpuid = arg;
 
-       tprintf(", %u", cpuid);
+       if (entering(tcp)) {
+               tprintf(", %u", cpuid);
+               if (dump_kvm_run_structure)
+                       return 0;
+       } else if (!syserror(tcp)) {
+               vcpu_register(tcp, tcp->u_rval, cpuid);
+       }
+
        return RVAL_IOCTL_DECODED | RVAL_FD;
 }
 
@@ -160,6 +322,53 @@ kvm_ioctl_decode_sregs(struct tcb *const tcp, const unsigned int code,
 }
 # endif /* HAVE_STRUCT_KVM_SREGS */
 
+# include "xlat/kvm_exit_reason.h"
+static void
+kvm_ioctl_run_attach_auxstr(struct tcb *const tcp,
+                           struct vcpu_info *info)
+
+{
+       static struct kvm_run vcpu_run_struct;
+
+       if (info->mmap_len < sizeof(vcpu_run_struct))
+               return;
+
+       if (umove(tcp, info->mmap_addr, &vcpu_run_struct) < 0)
+               return;
+
+       tcp->auxstr = xlat_idx(kvm_exit_reason, ARRAY_SIZE(kvm_exit_reason) - 1,
+                              vcpu_run_struct.exit_reason);
+       if (!tcp->auxstr)
+               tcp->auxstr = "KVM_EXIT_???";
+}
+
+static int
+kvm_ioctl_decode_run(struct tcb *const tcp)
+{
+
+       if (entering(tcp))
+               return 0;
+
+       int r = RVAL_DECODED;
+
+       if (syserror(tcp))
+               return r;
+
+       if (dump_kvm_run_structure) {
+               tcp->auxstr = NULL;
+               int fd = tcp->u_arg[0];
+               struct vcpu_info *info = vcpu_get_info(tcp, fd);
+
+               if (info) {
+                       kvm_ioctl_run_attach_auxstr(tcp, info);
+                       if (tcp->auxstr)
+                               r |= RVAL_STR;
+               }
+       }
+
+       return r;
+}
+
 int
 kvm_ioctl(struct tcb *const tcp, const unsigned int code, const kernel_ulong_t arg)
 {
@@ -195,7 +404,10 @@ kvm_ioctl(struct tcb *const tcp, const unsigned int code, const kernel_ulong_t a
 
        case KVM_CREATE_VM:
                return RVAL_DECODED | RVAL_FD;
+
        case KVM_RUN:
+               return kvm_ioctl_decode_run(tcp);
+
        case KVM_GET_VCPU_MMAP_SIZE:
        case KVM_GET_API_VERSION:
        default:
@@ -203,4 +415,11 @@ kvm_ioctl(struct tcb *const tcp, const unsigned int code, const kernel_ulong_t a
        }
 }
 
+void
+kvm_run_structure_decoder_init(void)
+{
+       dump_kvm_run_structure = true;
+       mmap_cache_enable();
+}
+
 #endif /* HAVE_LINUX_KVM_H */