From b1fd5f1039ffee9cfb676006c7cdc4fd265636a6 Mon Sep 17 00:00:00 2001
From: Steffen Schulz <steffen.schulz@intel.com>
Date: Wed, 14 Dec 2022 17:23:14 -0800
Subject: [PATCH] check ToPA allocation success

Check size returned for ToA allocation instead of blind mmap + assert.
Requires KVM-Nyx change to return error on allocation fail.
---
 nyx/pt.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/nyx/pt.c b/nyx/pt.c
index a706f74bb6..b7e9c2abb8 100644
--- a/nyx/pt.c
+++ b/nyx/pt.c
@@ -322,6 +322,11 @@ void pt_pre_kvm_run(CPUState *cpu)
             assert(cpu->pt_fd != -1);
             ret = ioctl(cpu->pt_fd, KVM_VMX_PT_GET_TOPA_SIZE, (unsigned long)0x0);
 
+            if (ret == -1) {
+                nyx_abort("ToPA allocation failure. Check kernel logs.\n");
+            }
+
+            assert(ret % PAGE_SIZE == 0);
             cpu->pt_mmap = mmap((void *)PT_BUFFER_MMAP_ADDR, ret,
                                 PROT_READ | PROT_WRITE, MAP_SHARED, cpu->pt_fd, 0);
             assert(cpu->pt_mmap != (void *)0xFFFFFFFFFFFFFFFF);