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>

diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index b53ee59748027b42ab9dc1b92209dabee0ebfb31..6a7b0a4d98632b86c05e70cc2aa7204c39fb22c2 100644 (file)
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -204,6 +204,18 @@ struct kvm_hyperv_exit {
        } u;
 };
 
+struct kvm_xen_exit {
+#define KVM_EXIT_XEN_HCALL             1
+       __u32 type;
+       union {
+               struct {
+                       __u64 input;
+                       __u64 result;
+                       __u64 params[5];
+               } hcall;
+       } u;
+};
+
 #define KVM_S390_GET_SKEYS_NONE   1
 #define KVM_S390_SKEYS_MAX        1048576
 
@@ -235,6 +247,7 @@ struct kvm_hyperv_exit {
 #define KVM_EXIT_S390_STSI        25
 #define KVM_EXIT_IOAPIC_EOI       26
 #define KVM_EXIT_HYPERV           27
+#define KVM_EXIT_XEN              28
 
 /* For KVM_EXIT_INTERNAL_ERROR */
 /* Emulate instruction failed. */
@@ -392,8 +405,9 @@ struct kvm_run {
                } eoi;
                /* KVM_EXIT_HYPERV */
                struct kvm_hyperv_exit hyperv;
+               struct kvm_xen_exit xen;
                /* Fix the size of the union. */
-               char padding[256];
+               char padding[196];
        };
 
        /* 2048 is the size of the char array used to bound/pad the size

diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index 4eb0629db577b90f77125a24a8d5ddfbdc1525f1..1271e78e61f369d532cfd18909de1c679977c9ba 100644 (file)
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -3712,6 +3712,9 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
         ioapic_eoi_broadcast(run->eoi.vector);
         ret = 0;
         break;
+    case KVM_EXIT_XEN:
+        ret = kvm_xen_handle_exit(cpu, &run->xen);
+        break;
     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 6a19a69af5d0a5bbff1c30047de265732462e231..aa7a5c6a5fb23cf6ff9564f230dfc8be3c378e2e 100644 (file)
--- a/target/i386/trace-events
+++ b/target/i386/trace-events
@@ -15,3 +15,6 @@ kvm_sev_launch_start(int policy, void *session, void *pdh) "policy 0x%x session
 kvm_sev_launch_update_data(void *addr, uint64_t len) "addr %p len 0x%" PRIu64
 kvm_sev_launch_measurement(const char *value) "data %s"
 kvm_sev_launch_finish(void) ""
+
+# target/i386/xen.c
+kvm_xen_hypercall(int cpu, uint64_t input, uint64_t a0, uint64_t a1, uint64_t a2, uint64_t ret) "xen_hypercall: cpu %d input %" PRIu64 " a0 0x%" PRIx64 " a1 0x%" PRIx64 " a2 0x%" PRIx64" ret 0x%" PRIu64

diff --git a/target/i386/xen.c b/target/i386/xen.c
index efd5b91309f37e9c74b315c19ddd5831497a62e1..8a4dd62bfa6becb26d202b7e190e6926f9c8af3e 100644 (file)
--- a/target/i386/xen.c
+++ b/target/i386/xen.c
@@ -10,10 +10,23 @@
 
 #include "qemu/osdep.h"
 #include "qemu/main-loop.h"
+#include "qemu/log.h"
 #include "linux/kvm.h"
 #include "cpu.h"
 #include "xen.h"
 
+#include "trace.h"
+
+/*
+ * Unhandled hypercalls error:
+ *
+ * -1 crash and dump registers
+ *  0 no abort and guest handles -ENOSYS (default)
+ */
+#ifndef HCALL_ERR
+#define HCALL_ERR      0
+#endif
+
 static void arch_init_hypercall_page(CPUState *cs, void *addr)
 {
     CPUX86State *env = cs->env_ptr;
@@ -61,3 +74,31 @@ int kvm_xen_set_hypercall_page(CPUState *env)
 
     return kvm_vm_ioctl(env->kvm_state, KVM_XEN_HVM_CONFIG, &cfg);
 }
+
+static int __kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit)
+{
+    uint16_t code = exit->u.hcall.input;
+
+    switch (code) {
+    default:
+        exit->u.hcall.result = -ENOSYS;
+        return HCALL_ERR;
+    }
+}
+
+int kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit)
+{
+    int ret = HCALL_ERR;
+
+    switch (exit->type) {
+    case KVM_EXIT_XEN_HCALL: {
+        ret = __kvm_xen_handle_exit(cpu, exit);
+        trace_kvm_xen_hypercall(CPU(cpu)->cpu_index, exit->u.hcall.input,
+                           exit->u.hcall.params[0], exit->u.hcall.params[1],
+                           exit->u.hcall.params[2], exit->u.hcall.result);
+        return ret;
+    }
+    default:
+        return ret;
+    }
+}

diff --git a/target/i386/xen.h b/target/i386/xen.h
index 4512e127000fe1dbb0644f5a89cad757ce097a83..025cab7badad23c2fbb1af13416afef901e886fa 100644 (file)
--- a/target/i386/xen.h
+++ b/target/i386/xen.h
@@ -22,5 +22,6 @@
 #define XEN_CPUID_HVM              0x40000004
 
 int kvm_xen_set_hypercall_page(CPUState *env);
+int kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit);
 
 #endif