From 79b7067dc6acec07d93407dd870268a5cd68924d Mon Sep 17 00:00:00 2001 From: Joao Martins Date: Fri, 20 Jul 2018 15:19:05 -0400 Subject: [PATCH] i386/xen: implement HYPERVISOR_sched_op, SCHEDOP_shutdown 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 [dwmw2: Ditch sched_op_compat which was never available for HVM guests, Add SCHEDOP_soft_reset] Signed-off-by: David Woodhouse Reviewed-by: Paul Durrant --- 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]); -- 2.11.4.GIT