[Qemu-devel] [PATCH v0 6/7] kvm: add vCPU failed memeory access processing

[Denis Plotnikov <dplotnikov@virtuozzo.com>]

Is done with support of the KVM patch returning the faulting address.

Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
---
 target/i386/kvm.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index 3ac5302bc5..b87881a8f1 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -45,6 +45,8 @@
 #include "hw/pci/msi.h"
 #include "hw/pci/msix.h"
 #include "migration/blocker.h"
+#include "migration/savevm.h"
+#include "migration/ram.h"
 #include "exec/memattrs.h"
 #include "trace.h"
 
@@ -3130,6 +3132,18 @@ static bool host_supports_vmx(void)
     return ecx & CPUID_EXT_VMX;
 }
 
+static int kvm_handle_fail_mem_access(CPUState *cpu)
+{
+    struct kvm_run *run = cpu->kvm_run;
+    int ret = ram_process_page_fault((void*)run->fail_mem_access.hva);
+
+    if (ret >= 0) {
+        cpu_resume(cpu);
+    }
+
+    return ret;
+}
+
 #define VMX_INVALID_GUEST_STATE 0x80000021
 
 int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
@@ -3188,6 +3202,10 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
         ioapic_eoi_broadcast(run->eoi.vector);
         ret = 0;
         break;
+    case KVM_EXIT_FAIL_MEM_ACCESS:
+        ret = kvm_handle_fail_mem_access(cs);
+        //ret = -1; -- to prevent further execution ret = 0; -- to continue without errors
+        break;
     default:
         fprintf(stderr, "KVM: unknown exit reason %d\n", run->exit_reason);
         ret = -1;
-- 
2.17.0