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 0d3eddf9de68d4fa0d2395874ae8e7ea5865e747..ebde6bc204431027895eddb34618fe7c6c73bb53 100644 (file)
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -5471,6 +5471,11 @@ 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/trace-events b/target/i386/trace-events
index 2cd8726eebb7d42b70a14ba3c128290b428847da..1bf95588115a87ad4e479f371e5bda4c4b417de2 100644 (file)
--- a/target/i386/trace-events
+++ b/target/i386/trace-events
@@ -11,3 +11,6 @@ kvm_sev_launch_measurement(const char *value) "data %s"
 kvm_sev_launch_finish(void) ""
 kvm_sev_launch_secret(uint64_t hpa, uint64_t hva, uint64_t secret, int len) "hpa 0x%" PRIx64 " hva 0x%" PRIx64 " data 0x%" PRIx64 " len %d"
 kvm_sev_attestation_report(const char *mnonce, const char *data) "mnonce %s data %s"
+
+# target/i386/xen.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/xen.c b/target/i386/xen.c
index bc183dce4edf3343d9b515c6858a45ce54130ae8..708ab908a0e97bd01506f2cd87580d51d659b4b0 100644 (file)
--- a/target/i386/xen.c
+++ b/target/i386/xen.c
@@ -10,8 +10,10 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/log.h"
 #include "kvm/kvm_i386.h"
 #include "xen.h"
+#include "trace.h"
 
 int kvm_xen_init(KVMState *s, uint32_t xen_version)
 {
@@ -47,3 +49,40 @@ int kvm_xen_init(KVMState *s, uint32_t xen_version)
 
     return 0;
 }
+
+static bool __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 (!__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_GUEST_ERROR, "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/xen.h b/target/i386/xen.h
index ae880c47bc095148725d7c1267abbcb910a2d619..9134d786851c80f3f4605a2b1577dfcd511d73be 100644 (file)
--- a/target/i386/xen.h
+++ b/target/i386/xen.h
@@ -23,5 +23,6 @@
 #define XEN_VERSION(maj, min) ((maj) << 16 | (min))
 
 int kvm_xen_init(KVMState *s, uint32_t xen_version);
+int kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit);
 
 #endif /* QEMU_I386_XEN_H */