From: Joao Martins <joao.m.mart...@oracle.com>
It allows to shutdown itself via hypercall with any of the 3 reasons:
1) self-reboot
2) shutdown
3) crash
Implementing SCHEDOP_shutdown sub op let us handle crashes gracefully rather
than leading to triple faults if it remains unimplemented.
In addition, the SHUTDOWN_soft_reset reason is used for kexec, to reset
Xen shared pages and other enlightenments and leave a clean slate for the
new kernel without the hypervisor helpfully writing information at
unexpected addresses.
Signed-off-by: Joao Martins <joao.m.mart...@oracle.com>
[dwmw2: Ditch sched_op_compat which was never available for HVM guests,
Add SCHEDOP_soft_reset]
Signed-off-by: David Woodhouse <d...@amazon.co.uk>
Reviewed-by: Paul Durrant <p...@xen.org>
---
include/sysemu/kvm_xen.h | 1 +
target/i386/kvm/trace-events | 1 +
target/i386/kvm/xen-emu.c | 75 ++++++++++++++++++++++++++++++++++++
3 files changed, 77 insertions(+)
diff --git a/include/sysemu/kvm_xen.h b/include/sysemu/kvm_xen.h
index 296533f2d5..5dffcc0542 100644
--- a/include/sysemu/kvm_xen.h
+++ b/include/sysemu/kvm_xen.h
@@ -12,6 +12,7 @@
#ifndef QEMU_SYSEMU_KVM_XEN_H
#define QEMU_SYSEMU_KVM_XEN_H
+int kvm_xen_soft_reset(void);
uint32_t kvm_xen_get_caps(void);
#define kvm_xen_has_cap(cap) (!!(kvm_xen_get_caps() & \
diff --git a/target/i386/kvm/trace-events b/target/i386/kvm/trace-events
index cd6f842b1f..bb732e1da8 100644
--- a/target/i386/kvm/trace-events
+++ b/target/i386/kvm/trace-events
@@ -8,3 +8,4 @@ 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
+kvm_xen_soft_reset(void) ""
diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c
index 56b80a7880..4ed833656f 100644
--- a/target/i386/kvm/xen-emu.c
+++ b/target/i386/kvm/xen-emu.c
@@ -11,14 +11,17 @@
#include "qemu/osdep.h"
#include "qemu/log.h"
+#include "qemu/main-loop.h"
#include "sysemu/kvm_int.h"
#include "sysemu/kvm_xen.h"
#include "kvm/kvm_i386.h"
#include "exec/address-spaces.h"
#include "xen-emu.h"
#include "trace.h"
+#include "sysemu/runstate.h"
#include "hw/xen/interface/version.h"
+#include "hw/xen/interface/sched.h"
static int kvm_gva_rw(CPUState *cs, uint64_t gva, void *_buf, size_t sz,
bool is_write)
@@ -170,6 +173,75 @@ static bool kvm_xen_hcall_xen_version(struct kvm_xen_exit
*exit, X86CPU *cpu,
return true;
}
+int kvm_xen_soft_reset(void)
+{
+ assert(qemu_mutex_iothread_locked());
+
+ trace_kvm_xen_soft_reset();
+
+ /* Nothing to reset... yet. */
+ return 0;
+}
+
+static int schedop_shutdown(CPUState *cs, uint64_t arg)
+{
+ struct sched_shutdown shutdown;
+ int ret = 0;
+
+ /* No need for 32/64 compat handling */
+ qemu_build_assert(sizeof(shutdown) == 4);
+
+ if (kvm_copy_from_gva(cs, arg, &shutdown, sizeof(shutdown))) {
+ return -EFAULT;
+ }
+
+ switch (shutdown.reason) {
+ case SHUTDOWN_crash:
+ cpu_dump_state(cs, stderr, CPU_DUMP_CODE);
+ qemu_system_guest_panicked(NULL);
+ break;
+
+ case SHUTDOWN_reboot:
+ qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
+ break;
+
+ case SHUTDOWN_poweroff:
+ qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
+ break;
+
+ case SHUTDOWN_soft_reset:
+ qemu_mutex_lock_iothread();
+ ret = kvm_xen_soft_reset();
+ qemu_mutex_unlock_iothread();
+ break;
+
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret;
+}
+
+static bool kvm_xen_hcall_sched_op(struct kvm_xen_exit *exit, X86CPU *cpu,
+ int cmd, uint64_t arg)
+{
+ CPUState *cs = CPU(cpu);
+ int err = -ENOSYS;
+
+ switch (cmd) {
+ case SCHEDOP_shutdown:
+ err = schedop_shutdown(cs, arg);
+ break;
+
+ default:
+ return false;
+ }
+
+ exit->u.hcall.result = err;
+ return true;
+}
+
static bool do_kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit)
{
uint16_t code = exit->u.hcall.input;
@@ -180,6 +252,9 @@ static bool do_kvm_xen_handle_exit(X86CPU *cpu, struct
kvm_xen_exit *exit)
}
switch (code) {
+ case __HYPERVISOR_sched_op:
+ return kvm_xen_hcall_sched_op(exit, cpu, exit->u.hcall.params[0],
+ exit->u.hcall.params[1]);
case __HYPERVISOR_xen_version:
return kvm_xen_hcall_xen_version(exit, cpu, exit->u.hcall.params[0],
exit->u.hcall.params[1]);
--
2.39.0
