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>
---
target/i386/kvm/xen-emu.c | 68 +++++++++++++++++++++++++++++++++++++++
1 file changed, 68 insertions(+)
diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c
index 1dea6feb90..5f2b55ef10 100644
--- a/target/i386/kvm/xen-emu.c
+++ b/target/i386/kvm/xen-emu.c
@@ -17,8 +17,10 @@
#include "exec/address-spaces.h"
#include "xen-emu.h"
#include "trace.h"
+#include "sysemu/runstate.h"
#include "standard-headers/xen/version.h"
+#include "standard-headers/xen/sched.h"
static int kvm_gva_rw(CPUState *cs, uint64_t gva, void *_buf, size_t sz,
bool is_write)
@@ -170,6 +172,69 @@ static bool kvm_xen_hcall_xen_version(struct kvm_xen_exit
*exit, X86CPU *cpu,
return true;
}
+static int kvm_xen_soft_reset(void)
+{
+ /* 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:
+ ret = kvm_xen_soft_reset();
+ 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 +245,9 @@ 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]);
--
2.35.3
