i386/xen: handle guest hypercalls

This means handling the new exit reason for Xen but still
crashing on purpose. As we implement each of the hypercalls
we will then return the right return code.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
[dwmw2: Add CPL to hypercall tracing, disallow hypercalls from CPL > 0]
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 5977edb1ca29516954e104b0e67e8c32ea99e06f..c37e44d88f6fcc59817fe3f9d31a0f70fdb93b94 100644 (file)
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -5466,6 +5466,11 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
         assert(run->msr.reason == KVM_MSR_EXIT_REASON_FILTER);
         ret = kvm_handle_wrmsr(cpu, run);
         break;
+#ifdef CONFIG_XEN_EMU
+    case KVM_EXIT_XEN:
+        ret = kvm_xen_handle_exit(cpu, &run->xen);
+        break;
+#endif
     default:
         fprintf(stderr, "KVM: unknown exit reason %d\n", run->exit_reason);
         ret = -1;

diff --git a/target/i386/kvm/trace-events b/target/i386/kvm/trace-events
index 7c369db1e15505fd5dafc6eaae810e191e255adf..cd6f842b1fd199b090b639b7a6423fdf382ad9a7 100644 (file)
--- a/target/i386/kvm/trace-events
+++ b/target/i386/kvm/trace-events
@@ -5,3 +5,6 @@ kvm_x86_fixup_msi_error(uint32_t gsi) "VT-d failed to remap interrupt for GSI %"
 kvm_x86_add_msi_route(int virq) "Adding route entry for virq %d"
 kvm_x86_remove_msi_route(int virq) "Removing route entry for virq %d"
 kvm_x86_update_msi_routes(int num) "Updated %d MSI routes"
+
+# xen-emu.c
+kvm_xen_hypercall(int cpu, uint8_t cpl, uint64_t input, uint64_t a0, uint64_t a1, uint64_t a2, uint64_t ret) "xen_hypercall: cpu %d cpl %d input %" PRIu64 " a0 0x%" PRIx64 " a1 0x%" PRIx64 " a2 0x%" PRIx64" ret 0x%" PRIx64

diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c
index 8433c4d70fe10bc960abf4030e7fa0bd26e6ef49..668713d5af6f793dc74c75472ba2172be3bc644f 100644 (file)
--- a/target/i386/kvm/xen-emu.c
+++ b/target/i386/kvm/xen-emu.c
@@ -10,9 +10,11 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/log.h"
 #include "sysemu/kvm_int.h"
 #include "kvm/kvm_i386.h"
 #include "xen-emu.h"
+#include "trace.h"
 
 int kvm_xen_init(KVMState *s, uint32_t hypercall_msr)
 {
@@ -48,3 +50,40 @@ int kvm_xen_init(KVMState *s, uint32_t hypercall_msr)
 
     return 0;
 }
+
+static bool do_kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit)
+{
+    uint16_t code = exit->u.hcall.input;
+
+    if (exit->u.hcall.cpl > 0) {
+        exit->u.hcall.result = -EPERM;
+        return true;
+    }
+
+    switch (code) {
+    default:
+        return false;
+    }
+}
+
+int kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit)
+{
+    if (exit->type != KVM_EXIT_XEN_HCALL)
+        return -1;
+
+    if (!do_kvm_xen_handle_exit(cpu, exit)) {
+        /* Some hypercalls will be deliberately "implemented" by returning
+         * -ENOSYS. This case is for hypercalls which are unexpected. */
+        exit->u.hcall.result = -ENOSYS;
+        qemu_log_mask(LOG_UNIMP, "Unimplemented Xen hypercall %"
+                      PRId64 " (0x%" PRIx64 " 0x%" PRIx64 " 0x%" PRIx64 ")\n",
+                      (uint64_t)exit->u.hcall.input, (uint64_t)exit->u.hcall.params[0],
+                      (uint64_t)exit->u.hcall.params[1], (uint64_t)exit->u.hcall.params[1]);
+    }
+
+    trace_kvm_xen_hypercall(CPU(cpu)->cpu_index, exit->u.hcall.cpl,
+                            exit->u.hcall.input, exit->u.hcall.params[0],
+                            exit->u.hcall.params[1], exit->u.hcall.params[2],
+                            exit->u.hcall.result);
+    return 0;
+}

diff --git a/target/i386/kvm/xen-emu.h b/target/i386/kvm/xen-emu.h
index 2101df01824bfccbbdc51f2dc08585d07cc67e8e..76a3de6c4d5301528e156e250ee2d69a2884f2d4 100644 (file)
--- a/target/i386/kvm/xen-emu.h
+++ b/target/i386/kvm/xen-emu.h
@@ -24,5 +24,6 @@
 #define XEN_VERSION(maj, min) ((maj) << 16 | (min))
 
 int kvm_xen_init(KVMState *s, uint32_t hypercall_msr);
+int kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit);
 
 #endif /* QEMU_I386_KVM_XEN_EMU_H */