i386/xen: handle VCPUOP_register_vcpu_info
Handle the hypercall to set a per vcpu info, and also wire up the default
vcpu_info in the shared_info page for the first 32 vCPUs.
To avoid deadlock within KVM a vCPU thread must set its *own* vcpu_info
rather than it being set from the context in which the hypercall is
invoked.
Add the vcpu_info (and default) GPA to the vmstate_x86_cpu for migration,
and restore it in kvm_arch_put_registers() appropriately.
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 5069adf..9070efd 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1799,6 +1799,8 @@
#endif
#if defined(CONFIG_KVM)
struct kvm_nested_state *nested_state;
+ uint64_t xen_vcpu_info_gpa;
+ uint64_t xen_vcpu_info_default_gpa;
#endif
#if defined(CONFIG_HVF)
HVFX86LazyFlags hvf_lflags;
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index f43e553..5a144ec 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -4750,6 +4750,15 @@
kvm_arch_set_tsc_khz(cpu);
}
+#ifdef CONFIG_XEN_EMU
+ if (xen_mode == XEN_EMULATE && level == KVM_PUT_FULL_STATE) {
+ ret = kvm_put_xen_state(cpu);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+#endif
+
ret = kvm_getput_regs(x86_cpu, 1);
if (ret < 0) {
return ret;
@@ -4849,6 +4858,14 @@
if (ret < 0) {
goto out;
}
+#ifdef CONFIG_XEN_EMU
+ if (xen_mode == XEN_EMULATE) {
+ ret = kvm_get_xen_state(cs);
+ if (ret < 0) {
+ goto out;
+ }
+ }
+#endif
ret = 0;
out:
cpu_sync_bndcs_hflags(&cpu->env);
diff --git a/target/i386/kvm/trace-events b/target/i386/kvm/trace-events
index 8e9f269..a840e03 100644
--- a/target/i386/kvm/trace-events
+++ b/target/i386/kvm/trace-events
@@ -10,3 +10,4 @@
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) ""
kvm_xen_set_shared_info(uint64_t gfn) "shared info at gfn 0x%" PRIx64
+kvm_xen_set_vcpu_attr(int cpu, int type, uint64_t gpa) "vcpu attr cpu %d type %d gpa 0x%" PRIx64
diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c
index e5ae0a9..30b4789 100644
--- a/target/i386/kvm/xen-emu.c
+++ b/target/i386/kvm/xen-emu.c
@@ -119,6 +119,8 @@
int kvm_xen_init_vcpu(CPUState *cs)
{
+ X86CPU *cpu = X86_CPU(cs);
+ CPUX86State *env = &cpu->env;
int err;
/*
@@ -142,6 +144,9 @@
}
}
+ env->xen_vcpu_info_gpa = INVALID_GPA;
+ env->xen_vcpu_info_default_gpa = INVALID_GPA;
+
return 0;
}
@@ -187,10 +192,58 @@
return true;
}
+static int kvm_xen_set_vcpu_attr(CPUState *cs, uint16_t type, uint64_t gpa)
+{
+ struct kvm_xen_vcpu_attr xhsi;
+
+ xhsi.type = type;
+ xhsi.u.gpa = gpa;
+
+ trace_kvm_xen_set_vcpu_attr(cs->cpu_index, type, gpa);
+
+ return kvm_vcpu_ioctl(cs, KVM_XEN_VCPU_SET_ATTR, &xhsi);
+}
+
+static void do_set_vcpu_info_default_gpa(CPUState *cs, run_on_cpu_data data)
+{
+ X86CPU *cpu = X86_CPU(cs);
+ CPUX86State *env = &cpu->env;
+
+ env->xen_vcpu_info_default_gpa = data.host_ulong;
+
+ /* Changing the default does nothing if a vcpu_info was explicitly set. */
+ if (env->xen_vcpu_info_gpa == INVALID_GPA) {
+ kvm_xen_set_vcpu_attr(cs, KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO,
+ env->xen_vcpu_info_default_gpa);
+ }
+}
+
+static void do_set_vcpu_info_gpa(CPUState *cs, run_on_cpu_data data)
+{
+ X86CPU *cpu = X86_CPU(cs);
+ CPUX86State *env = &cpu->env;
+
+ env->xen_vcpu_info_gpa = data.host_ulong;
+
+ kvm_xen_set_vcpu_attr(cs, KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO,
+ env->xen_vcpu_info_gpa);
+}
+
+static void do_vcpu_soft_reset(CPUState *cs, run_on_cpu_data data)
+{
+ X86CPU *cpu = X86_CPU(cs);
+ CPUX86State *env = &cpu->env;
+
+ env->xen_vcpu_info_gpa = INVALID_GPA;
+ env->xen_vcpu_info_default_gpa = INVALID_GPA;
+
+ kvm_xen_set_vcpu_attr(cs, KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO, INVALID_GPA);
+}
+
static int xen_set_shared_info(uint64_t gfn)
{
uint64_t gpa = gfn << TARGET_PAGE_BITS;
- int err;
+ int i, err;
QEMU_IOTHREAD_LOCK_GUARD();
@@ -207,6 +260,15 @@
trace_kvm_xen_set_shared_info(gfn);
+ for (i = 0; i < XEN_LEGACY_MAX_VCPUS; i++) {
+ CPUState *cpu = qemu_get_cpu(i);
+ if (cpu) {
+ async_run_on_cpu(cpu, do_set_vcpu_info_default_gpa,
+ RUN_ON_CPU_HOST_ULONG(gpa));
+ }
+ gpa += sizeof(vcpu_info_t);
+ }
+
return err;
}
@@ -364,15 +426,43 @@
}
}
+static int vcpuop_register_vcpu_info(CPUState *cs, CPUState *target,
+ uint64_t arg)
+{
+ struct vcpu_register_vcpu_info rvi;
+ uint64_t gpa;
+
+ /* No need for 32/64 compat handling */
+ qemu_build_assert(sizeof(rvi) == 16);
+ qemu_build_assert(sizeof(struct vcpu_info) == 64);
+
+ if (!target) {
+ return -ENOENT;
+ }
+
+ if (kvm_copy_from_gva(cs, arg, &rvi, sizeof(rvi))) {
+ return -EFAULT;
+ }
+
+ if (rvi.offset > TARGET_PAGE_SIZE - sizeof(struct vcpu_info)) {
+ return -EINVAL;
+ }
+
+ gpa = ((rvi.mfn << TARGET_PAGE_BITS) + rvi.offset);
+ async_run_on_cpu(target, do_set_vcpu_info_gpa, RUN_ON_CPU_HOST_ULONG(gpa));
+ return 0;
+}
+
static bool kvm_xen_hcall_vcpu_op(struct kvm_xen_exit *exit, X86CPU *cpu,
int cmd, int vcpu_id, uint64_t arg)
{
+ CPUState *dest = qemu_get_cpu(vcpu_id);
+ CPUState *cs = CPU(cpu);
int err;
switch (cmd) {
case VCPUOP_register_vcpu_info:
- /* no vcpu info placement for now */
- err = -ENOSYS;
+ err = vcpuop_register_vcpu_info(cs, dest, arg);
break;
default:
@@ -385,12 +475,17 @@
int kvm_xen_soft_reset(void)
{
+ CPUState *cpu;
int err;
assert(qemu_mutex_iothread_locked());
trace_kvm_xen_soft_reset();
+ CPU_FOREACH(cpu) {
+ async_run_on_cpu(cpu, do_vcpu_soft_reset, RUN_ON_CPU_NULL);
+ }
+
err = xen_overlay_map_shinfo_page(INVALID_GFN);
if (err) {
return err;
@@ -539,3 +634,55 @@
exit->u.hcall.result);
return 0;
}
+
+int kvm_put_xen_state(CPUState *cs)
+{
+ X86CPU *cpu = X86_CPU(cs);
+ CPUX86State *env = &cpu->env;
+ uint64_t gpa;
+ int ret;
+
+ gpa = env->xen_vcpu_info_gpa;
+ if (gpa == INVALID_GPA) {
+ gpa = env->xen_vcpu_info_default_gpa;
+ }
+
+ if (gpa != INVALID_GPA) {
+ ret = kvm_xen_set_vcpu_attr(cs, KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO, gpa);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+int kvm_get_xen_state(CPUState *cs)
+{
+ X86CPU *cpu = X86_CPU(cs);
+ CPUX86State *env = &cpu->env;
+ uint64_t gpa;
+
+ /*
+ * The kernel does not mark vcpu_info as dirty when it delivers interrupts
+ * to it. It's up to userspace to *assume* that any page shared thus is
+ * always considered dirty. The shared_info page is different since it's
+ * an overlay and migrated separately anyway.
+ */
+ gpa = env->xen_vcpu_info_gpa;
+ if (gpa == INVALID_GPA) {
+ gpa = env->xen_vcpu_info_default_gpa;
+ }
+ if (gpa != INVALID_GPA) {
+ MemoryRegionSection mrs = memory_region_find(get_system_memory(),
+ gpa,
+ sizeof(struct vcpu_info));
+ if (mrs.mr &&
+ !int128_lt(mrs.size, int128_make64(sizeof(struct vcpu_info)))) {
+ memory_region_set_dirty(mrs.mr, mrs.offset_within_region,
+ sizeof(struct vcpu_info));
+ }
+ }
+
+ return 0;
+}
diff --git a/target/i386/kvm/xen-emu.h b/target/i386/kvm/xen-emu.h
index 21faf6b..4526056 100644
--- a/target/i386/kvm/xen-emu.h
+++ b/target/i386/kvm/xen-emu.h
@@ -26,5 +26,7 @@
int kvm_xen_init(KVMState *s, uint32_t hypercall_msr);
int kvm_xen_init_vcpu(CPUState *cs);
int kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit);
+int kvm_put_xen_state(CPUState *cs);
+int kvm_get_xen_state(CPUState *cs);
#endif /* QEMU_I386_KVM_XEN_EMU_H */
diff --git a/target/i386/machine.c b/target/i386/machine.c
index 310b125..1215e61 100644
--- a/target/i386/machine.c
+++ b/target/i386/machine.c
@@ -6,8 +6,10 @@
#include "kvm/hyperv.h"
#include "hw/i386/x86.h"
#include "kvm/kvm_i386.h"
+#include "hw/xen/xen.h"
#include "sysemu/kvm.h"
+#include "sysemu/kvm_xen.h"
#include "sysemu/tcg.h"
#include "qemu/error-report.h"
@@ -1257,6 +1259,22 @@
}
};
+static bool xen_vcpu_needed(void *opaque)
+{
+ return (xen_mode == XEN_EMULATE);
+}
+
+static const VMStateDescription vmstate_xen_vcpu = {
+ .name = "cpu/xen_vcpu",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = xen_vcpu_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT64(env.xen_vcpu_info_gpa, X86CPU),
+ VMSTATE_UINT64(env.xen_vcpu_info_default_gpa, X86CPU),
+ VMSTATE_END_OF_LIST()
+ }
+};
#endif
static bool mcg_ext_ctl_needed(void *opaque)
@@ -1716,6 +1734,7 @@
#endif
#ifdef CONFIG_KVM
&vmstate_nested_state,
+ &vmstate_xen_vcpu,
#endif
&vmstate_msr_tsx_ctrl,
&vmstate_msr_intel_sgx,
