The ghcb_alloc() function in the SEV selftest library always returned the first GHCB from the pool, regardless of whether it was already in use. In a multi-vCPU test, this causes all vCPUs to share and corrupt the same GHCB, leading to unpredictable test failures.
Modify ghcb_alloc() to iterate through the pool and return the first entry that is not currently marked as in_use. Mark the selected entry as in use before returning it to prevent other vCPUs from allocating it.
Additionally, correct a minor bug in the memset call which was incorrectly taking the address of the ghcb pointer instead of using the pointer value itself.
This ensures that each vCPU in a test gets its own unique GHCB, allowing multi-threaded SEV-ES tests to run correctly.
Signed-off-by: Neeraj Upadhyay Neeraj.Upadhyay@amd.com --- tools/testing/selftests/kvm/lib/x86/sev.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/x86/sev.c b/tools/testing/selftests/kvm/lib/x86/sev.c index de36a6c93839..3090a6518066 100644 --- a/tools/testing/selftests/kvm/lib/x86/sev.c +++ b/tools/testing/selftests/kvm/lib/x86/sev.c @@ -68,7 +68,6 @@ static void sev_es_terminate(void)
static struct ghcb_entry *ghcb_alloc(void) { - return &ghcb_pool->ghcbs[0]; struct ghcb_entry *entry; struct ghcb *ghcb; int i; @@ -81,7 +80,7 @@ static struct ghcb_entry *ghcb_alloc(void) entry = &ghcb_pool->ghcbs[i]; ghcb = &entry->ghcb;
- memset(&ghcb, 0, sizeof(*ghcb)); + memset(ghcb, 0, sizeof(*ghcb)); ghcb->ghcb_usage = 0; ghcb->protocol_version = 1;