[Qemu-devel] [PULL 31/34] WHXP Removes the use of WHvGetExitContextSize

[Paolo Bonzini <pbonzini@redhat.com>]

From: "Justin Terry (VM) via Qemu-devel" <qemu-devel@nongnu.org>

The use of WHvGetExitContextSize will break ABI compatibility if the platform
changes the context size while a qemu compiled executable does not recompile.
To avoid this we now use sizeof and let the platform determine which version
of the struction was passed for ABI compatibility.

Signed-off-by: Justin Terry (VM) <juterry@microsoft.com>
Message-Id: <1519665216-1078-8-git-send-email-juterry@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Justin Terry (VM) via Qemu-devel <qemu-devel@nongnu.org>
---
 target/i386/whpx-all.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/target/i386/whpx-all.c b/target/i386/whpx-all.c
index 47a6935..24387be 100644
--- a/target/i386/whpx-all.c
+++ b/target/i386/whpx-all.c
@@ -32,7 +32,6 @@
 struct whpx_state {
     uint64_t mem_quota;
     WHV_PARTITION_HANDLE partition;
-    uint32_t exit_ctx_size;
 };
 
 static const WHV_REGISTER_NAME whpx_register_names[] = {
@@ -899,7 +898,7 @@ static int whpx_vcpu_run(CPUState *cpu)
         }
 
         hr = WHvRunVirtualProcessor(whpx->partition, cpu->cpu_index,
-                                    &vcpu->exit_ctx, whpx->exit_ctx_size);
+                                    &vcpu->exit_ctx, sizeof(vcpu->exit_ctx));
 
         if (FAILED(hr)) {
             error_report("WHPX: Failed to exec a virtual processor,"
@@ -1042,8 +1041,7 @@ int whpx_init_vcpu(CPUState *cpu)
         }
     }
 
-    vcpu = g_malloc0(FIELD_OFFSET(struct whpx_vcpu, exit_ctx) +
-                     whpx->exit_ctx_size);
+    vcpu = g_malloc0(sizeof(struct whpx_vcpu));
 
     if (!vcpu) {
         error_report("WHPX: Failed to allocte VCPU context.");
@@ -1300,9 +1298,6 @@ static int whpx_accel_init(MachineState *ms)
         goto error;
     }
 
-    whpx->exit_ctx_size = WHvGetRunExitContextSize();
-    assert(whpx->exit_ctx_size);
-
     whpx_memory_init();
 
     cpu_interrupt_handler = whpx_handle_interrupt;
-- 
1.8.3.1