summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--tools/testing/selftests/kvm/lib/x86_64/processor.c18
1 files changed, 17 insertions, 1 deletions
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index c39a4353ba19..c09cd151fbe0 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -5,6 +5,7 @@
* Copyright (C) 2018, Google LLC.
*/
+#include "linux/bitmap.h"
#include "test_util.h"
#include "kvm_util.h"
#include "processor.h"
@@ -573,6 +574,21 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id,
DEFAULT_GUEST_STACK_VADDR_MIN,
MEM_REGION_DATA);
+ stack_vaddr += DEFAULT_STACK_PGS * getpagesize();
+
+ /*
+ * Align stack to match calling sequence requirements in section "The
+ * Stack Frame" of the System V ABI AMD64 Architecture Processor
+ * Supplement, which requires the value (%rsp + 8) to be a multiple of
+ * 16 when control is transferred to the function entry point.
+ *
+ * If this code is ever used to launch a vCPU with 32-bit entry point it
+ * may need to subtract 4 bytes instead of 8 bytes.
+ */
+ TEST_ASSERT(IS_ALIGNED(stack_vaddr, PAGE_SIZE),
+ "__vm_vaddr_alloc() did not provide a page-aligned address");
+ stack_vaddr -= 8;
+
vcpu = __vm_vcpu_add(vm, vcpu_id);
vcpu_init_cpuid(vcpu, kvm_get_supported_cpuid());
vcpu_setup(vm, vcpu);
@@ -580,7 +596,7 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id,
/* Setup guest general purpose registers */
vcpu_regs_get(vcpu, &regs);
regs.rflags = regs.rflags | 0x2;
- regs.rsp = stack_vaddr + (DEFAULT_STACK_PGS * getpagesize());
+ regs.rsp = stack_vaddr;
regs.rip = (unsigned long) guest_code;
vcpu_regs_set(vcpu, &regs);