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2aff696b10
qemu/target/i386/kvm/xen-emu.c
David Woodhouse 2aff696b10 hw/xen: Support HVM_PARAM_CALLBACK_TYPE_PCI_INTX callback 
The guest is permitted to specify an arbitrary domain/bus/device/function
and INTX pin from which the callback IRQ shall appear to have come.

In QEMU we can only easily do this for devices that actually exist, and
even that requires us "knowing" that it's a PCMachine in order to find
the PCI root bus — although that's OK really because it's always true.

We also don't get to get notified of INTX routing changes, because we
can't do that as a passive observer; if we try to register a notifier
it will overwrite any existing notifier callback on the device.

But in practice, guests using PCI_INTX will only ever use pin A on the
Xen platform device, and won't swizzle the INTX routing after they set
it up. So this is just fine.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01 09:07:50 +00:00

1347 lines
36 KiB
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/*
* Xen HVM emulation support in KVM
*
* Copyright © 2019 Oracle and/or its affiliates. All rights reserved.
* Copyright © 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "qemu/log.h"
#include "qemu/main-loop.h"
#include "hw/xen/xen.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/pci/msi.h"
#include "hw/i386/apic-msidef.h"
#include "hw/i386/kvm/xen_overlay.h"
#include "hw/i386/kvm/xen_evtchn.h"
#include "hw/xen/interface/version.h"
#include "hw/xen/interface/sched.h"
#include "hw/xen/interface/memory.h"
#include "hw/xen/interface/hvm/hvm_op.h"
#include "hw/xen/interface/hvm/params.h"
#include "hw/xen/interface/vcpu.h"
#include "hw/xen/interface/event_channel.h"
#include "xen-compat.h"
#ifdef TARGET_X86_64
#define hypercall_compat32(longmode) (!(longmode))
#else
#define hypercall_compat32(longmode) (false)
#endif
static bool kvm_gva_to_gpa(CPUState *cs, uint64_t gva, uint64_t *gpa,
size_t *len, bool is_write)
{
struct kvm_translation tr = {
.linear_address = gva,
};
if (len) {
*len = TARGET_PAGE_SIZE - (gva & ~TARGET_PAGE_MASK);
}
if (kvm_vcpu_ioctl(cs, KVM_TRANSLATE, &tr) || !tr.valid ||
(is_write && !tr.writeable)) {
return false;
}
*gpa = tr.physical_address;
return true;
}
static int kvm_gva_rw(CPUState *cs, uint64_t gva, void *_buf, size_t sz,
bool is_write)
{
uint8_t *buf = (uint8_t *)_buf;
uint64_t gpa;
size_t len;
while (sz) {
if (!kvm_gva_to_gpa(cs, gva, &gpa, &len, is_write)) {
return -EFAULT;
}
if (len > sz) {
len = sz;
}
cpu_physical_memory_rw(gpa, buf, len, is_write);
buf += len;
sz -= len;
gva += len;
}
return 0;
}
static inline int kvm_copy_from_gva(CPUState *cs, uint64_t gva, void *buf,
size_t sz)
{
return kvm_gva_rw(cs, gva, buf, sz, false);
}
static inline int kvm_copy_to_gva(CPUState *cs, uint64_t gva, void *buf,
size_t sz)
{
return kvm_gva_rw(cs, gva, buf, sz, true);
}
int kvm_xen_init(KVMState *s, uint32_t hypercall_msr)
{
const int required_caps = KVM_XEN_HVM_CONFIG_HYPERCALL_MSR |
KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL | KVM_XEN_HVM_CONFIG_SHARED_INFO;
struct kvm_xen_hvm_config cfg = {
.msr = hypercall_msr,
.flags = KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL,
};
int xen_caps, ret;
xen_caps = kvm_check_extension(s, KVM_CAP_XEN_HVM);
if (required_caps & ~xen_caps) {
error_report("kvm: Xen HVM guest support not present or insufficient");
return -ENOSYS;
}
if (xen_caps & KVM_XEN_HVM_CONFIG_EVTCHN_SEND) {
struct kvm_xen_hvm_attr ha = {
.type = KVM_XEN_ATTR_TYPE_XEN_VERSION,
.u.xen_version = s->xen_version,
};
(void)kvm_vm_ioctl(s, KVM_XEN_HVM_SET_ATTR, &ha);
cfg.flags |= KVM_XEN_HVM_CONFIG_EVTCHN_SEND;
}
ret = kvm_vm_ioctl(s, KVM_XEN_HVM_CONFIG, &cfg);
if (ret < 0) {
error_report("kvm: Failed to enable Xen HVM support: %s",
strerror(-ret));
return ret;
}
/* If called a second time, don't repeat the rest of the setup. */
if (s->xen_caps) {
return 0;
}
/*
* Event channel delivery via GSI/PCI_INTX needs to poll the vcpu_info
* of vCPU0 to deassert the IRQ when ->evtchn_upcall_pending is cleared.
*
* In the kernel, there's a notifier hook on the PIC/IOAPIC which allows
* such things to be polled at precisely the right time. We *could* do
* it nicely in the kernel: check vcpu_info[0]->evtchn_upcall_pending at
* the moment the IRQ is acked, and see if it should be reasserted.
*
* But the in-kernel irqchip is deprecated, so we're unlikely to add
* that support in the kernel. Insist on using the split irqchip mode
* instead.
*
* This leaves us polling for the level going low in QEMU, which lacks
* the appropriate hooks in its PIC/IOAPIC code. Even VFIO is sending a
* spurious 'ack' to an INTX IRQ every time there's any MMIO access to
* the device (for which it has to unmap the device and trap access, for
* some period after an IRQ!!). In the Xen case, we do it on exit from
* KVM_RUN, if the flag is set to say that the GSI is currently asserted.
* Which is kind of icky, but less so than the VFIO one. I may fix them
* both later...
*/
if (!kvm_kernel_irqchip_split()) {
error_report("kvm: Xen support requires kernel-irqchip=split");
return -EINVAL;
}
s->xen_caps = xen_caps;
return 0;
}
int kvm_xen_init_vcpu(CPUState *cs)
{
X86CPU *cpu = X86_CPU(cs);
CPUX86State *env = &cpu->env;
int err;
/*
* The kernel needs to know the Xen/ACPI vCPU ID because that's
* what the guest uses in hypercalls such as timers. It doesn't
* match the APIC ID which is generally used for talking to the
* kernel about vCPUs. And if vCPU threads race with creating
* their KVM vCPUs out of order, it doesn't necessarily match
* with the kernel's internal vCPU indices either.
*/
if (kvm_xen_has_cap(EVTCHN_SEND)) {
struct kvm_xen_vcpu_attr va = {
.type = KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID,
.u.vcpu_id = cs->cpu_index,
};
err = kvm_vcpu_ioctl(cs, KVM_XEN_VCPU_SET_ATTR, &va);
if (err) {
error_report("kvm: Failed to set Xen vCPU ID attribute: %s",
strerror(-err));
return err;
}
}
env->xen_vcpu_info_gpa = INVALID_GPA;
env->xen_vcpu_info_default_gpa = INVALID_GPA;
env->xen_vcpu_time_info_gpa = INVALID_GPA;
env->xen_vcpu_runstate_gpa = INVALID_GPA;
return 0;
}
uint32_t kvm_xen_get_caps(void)
{
return kvm_state->xen_caps;
}
static bool kvm_xen_hcall_xen_version(struct kvm_xen_exit *exit, X86CPU *cpu,
int cmd, uint64_t arg)
{
int err = 0;
switch (cmd) {
case XENVER_get_features: {
struct xen_feature_info fi;
/* No need for 32/64 compat handling */
qemu_build_assert(sizeof(fi) == 8);
err = kvm_copy_from_gva(CPU(cpu), arg, &fi, sizeof(fi));
if (err) {
break;
}
fi.submap = 0;
if (fi.submap_idx == 0) {
fi.submap |= 1 << XENFEAT_writable_page_tables |
1 << XENFEAT_writable_descriptor_tables |
1 << XENFEAT_auto_translated_physmap |
1 << XENFEAT_supervisor_mode_kernel |
1 << XENFEAT_hvm_callback_vector;
}
err = kvm_copy_to_gva(CPU(cpu), arg, &fi, sizeof(fi));
break;
}
default:
return false;
}
exit->u.hcall.result = err;
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 int kvm_xen_set_vcpu_callback_vector(CPUState *cs)
{
uint8_t vector = X86_CPU(cs)->env.xen_vcpu_callback_vector;
struct kvm_xen_vcpu_attr xva;
xva.type = KVM_XEN_VCPU_ATTR_TYPE_UPCALL_VECTOR;
xva.u.vector = vector;
trace_kvm_xen_set_vcpu_callback(cs->cpu_index, vector);
return kvm_vcpu_ioctl(cs, KVM_XEN_HVM_SET_ATTR, &xva);
}
static void do_set_vcpu_callback_vector(CPUState *cs, run_on_cpu_data data)
{
X86CPU *cpu = X86_CPU(cs);
CPUX86State *env = &cpu->env;
env->xen_vcpu_callback_vector = data.host_int;
if (kvm_xen_has_cap(EVTCHN_SEND)) {
kvm_xen_set_vcpu_callback_vector(cs);
}
}
static int set_vcpu_info(CPUState *cs, uint64_t gpa)
{
X86CPU *cpu = X86_CPU(cs);
CPUX86State *env = &cpu->env;
MemoryRegionSection mrs = { .mr = NULL };
void *vcpu_info_hva = NULL;
int ret;
ret = kvm_xen_set_vcpu_attr(cs, KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO, gpa);
if (ret || gpa == INVALID_GPA) {
goto out;
}
mrs = memory_region_find(get_system_memory(), gpa,
sizeof(struct vcpu_info));
if (mrs.mr && mrs.mr->ram_block &&
!int128_lt(mrs.size, int128_make64(sizeof(struct vcpu_info)))) {
vcpu_info_hva = qemu_map_ram_ptr(mrs.mr->ram_block,
mrs.offset_within_region);
}
if (!vcpu_info_hva) {
if (mrs.mr) {
memory_region_unref(mrs.mr);
mrs.mr = NULL;
}
ret = -EINVAL;
}
out:
if (env->xen_vcpu_info_mr) {
memory_region_unref(env->xen_vcpu_info_mr);
}
env->xen_vcpu_info_hva = vcpu_info_hva;
env->xen_vcpu_info_mr = mrs.mr;
return ret;
}
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) {
set_vcpu_info(cs, 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;
set_vcpu_info(cs, env->xen_vcpu_info_gpa);
}
void *kvm_xen_get_vcpu_info_hva(uint32_t vcpu_id)
{
CPUState *cs = qemu_get_cpu(vcpu_id);
if (!cs) {
return NULL;
}
return X86_CPU(cs)->env.xen_vcpu_info_hva;
}
void kvm_xen_maybe_deassert_callback(CPUState *cs)
{
CPUX86State *env = &X86_CPU(cs)->env;
struct vcpu_info *vi = env->xen_vcpu_info_hva;
if (!vi) {
return;
}
/* If the evtchn_upcall_pending flag is cleared, turn the GSI off. */
if (!vi->evtchn_upcall_pending) {
qemu_mutex_lock_iothread();
/*
* Check again now we have the lock, because it may have been
* asserted in the interim. And we don't want to take the lock
* every time because this is a fast path.
*/
if (!vi->evtchn_upcall_pending) {
X86_CPU(cs)->env.xen_callback_asserted = false;
xen_evtchn_set_callback_level(0);
}
qemu_mutex_unlock_iothread();
}
}
void kvm_xen_set_callback_asserted(void)
{
CPUState *cs = qemu_get_cpu(0);
if (cs) {
X86_CPU(cs)->env.xen_callback_asserted = true;
}
}
void kvm_xen_inject_vcpu_callback_vector(uint32_t vcpu_id, int type)
{
CPUState *cs = qemu_get_cpu(vcpu_id);
uint8_t vector;
if (!cs) {
return;
}
vector = X86_CPU(cs)->env.xen_vcpu_callback_vector;
if (vector) {
/*
* The per-vCPU callback vector injected via lapic. Just
* deliver it as an MSI.
*/
MSIMessage msg = {
.address = APIC_DEFAULT_ADDRESS | X86_CPU(cs)->apic_id,
.data = vector | (1UL << MSI_DATA_LEVEL_SHIFT),
};
kvm_irqchip_send_msi(kvm_state, msg);
return;
}
switch (type) {
case HVM_PARAM_CALLBACK_TYPE_VECTOR:
/*
* If the evtchn_upcall_pending field in the vcpu_info is set, then
* KVM will automatically deliver the vector on entering the vCPU
* so all we have to do is kick it out.
*/
qemu_cpu_kick(cs);
break;
case HVM_PARAM_CALLBACK_TYPE_GSI:
case HVM_PARAM_CALLBACK_TYPE_PCI_INTX:
if (vcpu_id == 0) {
xen_evtchn_set_callback_level(1);
}
break;
}
}
static int kvm_xen_set_vcpu_timer(CPUState *cs)
{
X86CPU *cpu = X86_CPU(cs);
CPUX86State *env = &cpu->env;
struct kvm_xen_vcpu_attr va = {
.type = KVM_XEN_VCPU_ATTR_TYPE_TIMER,
.u.timer.port = env->xen_virq[VIRQ_TIMER],
.u.timer.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL,
.u.timer.expires_ns = env->xen_singleshot_timer_ns,
};
return kvm_vcpu_ioctl(cs, KVM_XEN_VCPU_SET_ATTR, &va);
}
static void do_set_vcpu_timer_virq(CPUState *cs, run_on_cpu_data data)
{
kvm_xen_set_vcpu_timer(cs);
}
int kvm_xen_set_vcpu_virq(uint32_t vcpu_id, uint16_t virq, uint16_t port)
{
CPUState *cs = qemu_get_cpu(vcpu_id);
if (!cs) {
return -ENOENT;
}
/* cpu.h doesn't include the actual Xen header. */
qemu_build_assert(NR_VIRQS == XEN_NR_VIRQS);
if (virq >= NR_VIRQS) {
return -EINVAL;
}
if (port && X86_CPU(cs)->env.xen_virq[virq]) {
return -EEXIST;
}
X86_CPU(cs)->env.xen_virq[virq] = port;
if (virq == VIRQ_TIMER && kvm_xen_has_cap(EVTCHN_SEND)) {
async_run_on_cpu(cs, do_set_vcpu_timer_virq,
RUN_ON_CPU_HOST_INT(port));
}
return 0;
}
static void do_set_vcpu_time_info_gpa(CPUState *cs, run_on_cpu_data data)
{
X86CPU *cpu = X86_CPU(cs);
CPUX86State *env = &cpu->env;
env->xen_vcpu_time_info_gpa = data.host_ulong;
kvm_xen_set_vcpu_attr(cs, KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO,
env->xen_vcpu_time_info_gpa);
}
static void do_set_vcpu_runstate_gpa(CPUState *cs, run_on_cpu_data data)
{
X86CPU *cpu = X86_CPU(cs);
CPUX86State *env = &cpu->env;
env->xen_vcpu_runstate_gpa = data.host_ulong;
kvm_xen_set_vcpu_attr(cs, KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR,
env->xen_vcpu_runstate_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;
env->xen_vcpu_time_info_gpa = INVALID_GPA;
env->xen_vcpu_runstate_gpa = INVALID_GPA;
env->xen_vcpu_callback_vector = 0;
env->xen_singleshot_timer_ns = 0;
memset(env->xen_virq, 0, sizeof(env->xen_virq));
set_vcpu_info(cs, INVALID_GPA);
kvm_xen_set_vcpu_attr(cs, KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO,
INVALID_GPA);
kvm_xen_set_vcpu_attr(cs, KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR,
INVALID_GPA);
if (kvm_xen_has_cap(EVTCHN_SEND)) {
kvm_xen_set_vcpu_callback_vector(cs);
kvm_xen_set_vcpu_timer(cs);
}
}
static int xen_set_shared_info(uint64_t gfn)
{
uint64_t gpa = gfn << TARGET_PAGE_BITS;
int i, err;
QEMU_IOTHREAD_LOCK_GUARD();
/*
* The xen_overlay device tells KVM about it too, since it had to
* do that on migration load anyway (unless we're going to jump
* through lots of hoops to maintain the fiction that this isn't
* KVM-specific.
*/
err = xen_overlay_map_shinfo_page(gpa);
if (err) {
return err;
}
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;
}
static int add_to_physmap_one(uint32_t space, uint64_t idx, uint64_t gfn)
{
switch (space) {
case XENMAPSPACE_shared_info:
if (idx > 0) {
return -EINVAL;
}
return xen_set_shared_info(gfn);
case XENMAPSPACE_grant_table:
case XENMAPSPACE_gmfn:
case XENMAPSPACE_gmfn_range:
return -ENOTSUP;
case XENMAPSPACE_gmfn_foreign:
case XENMAPSPACE_dev_mmio:
return -EPERM;
default:
return -EINVAL;
}
}
static int do_add_to_physmap(struct kvm_xen_exit *exit, X86CPU *cpu,
uint64_t arg)
{
struct xen_add_to_physmap xatp;
CPUState *cs = CPU(cpu);
if (hypercall_compat32(exit->u.hcall.longmode)) {
struct compat_xen_add_to_physmap xatp32;
qemu_build_assert(sizeof(struct compat_xen_add_to_physmap) == 16);
if (kvm_copy_from_gva(cs, arg, &xatp32, sizeof(xatp32))) {
return -EFAULT;
}
xatp.domid = xatp32.domid;
xatp.size = xatp32.size;
xatp.space = xatp32.space;
xatp.idx = xatp32.idx;
xatp.gpfn = xatp32.gpfn;
} else {
if (kvm_copy_from_gva(cs, arg, &xatp, sizeof(xatp))) {
return -EFAULT;
}
}
if (xatp.domid != DOMID_SELF && xatp.domid != xen_domid) {
return -ESRCH;
}
return add_to_physmap_one(xatp.space, xatp.idx, xatp.gpfn);
}
static int do_add_to_physmap_batch(struct kvm_xen_exit *exit, X86CPU *cpu,
uint64_t arg)
{
struct xen_add_to_physmap_batch xatpb;
unsigned long idxs_gva, gpfns_gva, errs_gva;
CPUState *cs = CPU(cpu);
size_t op_sz;
if (hypercall_compat32(exit->u.hcall.longmode)) {
struct compat_xen_add_to_physmap_batch xatpb32;
qemu_build_assert(sizeof(struct compat_xen_add_to_physmap_batch) == 20);
if (kvm_copy_from_gva(cs, arg, &xatpb32, sizeof(xatpb32))) {
return -EFAULT;
}
xatpb.domid = xatpb32.domid;
xatpb.space = xatpb32.space;
xatpb.size = xatpb32.size;
idxs_gva = xatpb32.idxs.c;
gpfns_gva = xatpb32.gpfns.c;
errs_gva = xatpb32.errs.c;
op_sz = sizeof(uint32_t);
} else {
if (kvm_copy_from_gva(cs, arg, &xatpb, sizeof(xatpb))) {
return -EFAULT;
}
op_sz = sizeof(unsigned long);
idxs_gva = (unsigned long)xatpb.idxs.p;
gpfns_gva = (unsigned long)xatpb.gpfns.p;
errs_gva = (unsigned long)xatpb.errs.p;
}
if (xatpb.domid != DOMID_SELF && xatpb.domid != xen_domid) {
return -ESRCH;
}
/* Explicitly invalid for the batch op. Not that we implement it anyway. */
if (xatpb.space == XENMAPSPACE_gmfn_range) {
return -EINVAL;
}
while (xatpb.size--) {
unsigned long idx = 0;
unsigned long gpfn = 0;
int err;
/* For 32-bit compat this only copies the low 32 bits of each */
if (kvm_copy_from_gva(cs, idxs_gva, &idx, op_sz) ||
kvm_copy_from_gva(cs, gpfns_gva, &gpfn, op_sz)) {
return -EFAULT;
}
idxs_gva += op_sz;
gpfns_gva += op_sz;
err = add_to_physmap_one(xatpb.space, idx, gpfn);
if (kvm_copy_to_gva(cs, errs_gva, &err, sizeof(err))) {
return -EFAULT;
}
errs_gva += sizeof(err);
}
return 0;
}
static bool kvm_xen_hcall_memory_op(struct kvm_xen_exit *exit, X86CPU *cpu,
int cmd, uint64_t arg)
{
int err;
switch (cmd) {
case XENMEM_add_to_physmap:
err = do_add_to_physmap(exit, cpu, arg);
break;
case XENMEM_add_to_physmap_batch:
err = do_add_to_physmap_batch(exit, cpu, arg);
break;
default:
return false;
}
exit->u.hcall.result = err;
return true;
}
static bool handle_set_param(struct kvm_xen_exit *exit, X86CPU *cpu,
uint64_t arg)
{
CPUState *cs = CPU(cpu);
struct xen_hvm_param hp;
int err = 0;
/* No need for 32/64 compat handling */
qemu_build_assert(sizeof(hp) == 16);
if (kvm_copy_from_gva(cs, arg, &hp, sizeof(hp))) {
err = -EFAULT;
goto out;
}
if (hp.domid != DOMID_SELF && hp.domid != xen_domid) {
err = -ESRCH;
goto out;
}
switch (hp.index) {
case HVM_PARAM_CALLBACK_IRQ:
qemu_mutex_lock_iothread();
err = xen_evtchn_set_callback_param(hp.value);
qemu_mutex_unlock_iothread();
xen_set_long_mode(exit->u.hcall.longmode);
break;
default:
return false;
}
out:
exit->u.hcall.result = err;
return true;
}
static int kvm_xen_hcall_evtchn_upcall_vector(struct kvm_xen_exit *exit,
X86CPU *cpu, uint64_t arg)
{
struct xen_hvm_evtchn_upcall_vector up;
CPUState *target_cs;
/* No need for 32/64 compat handling */
qemu_build_assert(sizeof(up) == 8);
if (kvm_copy_from_gva(CPU(cpu), arg, &up, sizeof(up))) {
return -EFAULT;
}
if (up.vector < 0x10) {
return -EINVAL;
}
target_cs = qemu_get_cpu(up.vcpu);
if (!target_cs) {
return -EINVAL;
}
async_run_on_cpu(target_cs, do_set_vcpu_callback_vector,
RUN_ON_CPU_HOST_INT(up.vector));
return 0;
}
static bool kvm_xen_hcall_hvm_op(struct kvm_xen_exit *exit, X86CPU *cpu,
int cmd, uint64_t arg)
{
int ret = -ENOSYS;
switch (cmd) {
case HVMOP_set_evtchn_upcall_vector:
ret = kvm_xen_hcall_evtchn_upcall_vector(exit, cpu,
exit->u.hcall.params[0]);
break;
case HVMOP_pagetable_dying:
ret = -ENOSYS;
break;
case HVMOP_set_param:
return handle_set_param(exit, cpu, arg);
default:
return false;
}
exit->u.hcall.result = ret;
return true;
}
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 int vcpuop_register_vcpu_time_info(CPUState *cs, CPUState *target,
uint64_t arg)
{
struct vcpu_register_time_memory_area tma;
uint64_t gpa;
size_t len;
/* No need for 32/64 compat handling */
qemu_build_assert(sizeof(tma) == 8);
qemu_build_assert(sizeof(struct vcpu_time_info) == 32);
if (!target) {
return -ENOENT;
}
if (kvm_copy_from_gva(cs, arg, &tma, sizeof(tma))) {
return -EFAULT;
}
/*
* Xen actually uses the GVA and does the translation through the guest
* page tables each time. But Linux/KVM uses the GPA, on the assumption
* that guests only ever use *global* addresses (kernel virtual addresses)
* for it. If Linux is changed to redo the GVA→GPA translation each time,
* it will offer a new vCPU attribute for that, and we'll use it instead.
*/
if (!kvm_gva_to_gpa(cs, tma.addr.p, &gpa, &len, false) ||
len < sizeof(struct vcpu_time_info)) {
return -EFAULT;
}
async_run_on_cpu(target, do_set_vcpu_time_info_gpa,
RUN_ON_CPU_HOST_ULONG(gpa));
return 0;
}
static int vcpuop_register_runstate_info(CPUState *cs, CPUState *target,
uint64_t arg)
{
struct vcpu_register_runstate_memory_area rma;
uint64_t gpa;
size_t len;
/* No need for 32/64 compat handling */
qemu_build_assert(sizeof(rma) == 8);
/* The runstate area actually does change size, but Linux copes. */
if (!target) {
return -ENOENT;
}
if (kvm_copy_from_gva(cs, arg, &rma, sizeof(rma))) {
return -EFAULT;
}
/* As with vcpu_time_info, Xen actually uses the GVA but KVM doesn't. */
if (!kvm_gva_to_gpa(cs, rma.addr.p, &gpa, &len, false)) {
return -EFAULT;
}
async_run_on_cpu(target, do_set_vcpu_runstate_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_runstate_memory_area:
err = vcpuop_register_runstate_info(cs, dest, arg);
break;
case VCPUOP_register_vcpu_time_memory_area:
err = vcpuop_register_vcpu_time_info(cs, dest, arg);
break;
case VCPUOP_register_vcpu_info:
err = vcpuop_register_vcpu_info(cs, dest, arg);
break;
default:
return false;
}
exit->u.hcall.result = err;
return true;
}
static bool kvm_xen_hcall_evtchn_op(struct kvm_xen_exit *exit, X86CPU *cpu,
int cmd, uint64_t arg)
{
CPUState *cs = CPU(cpu);
int err = -ENOSYS;
switch (cmd) {
case EVTCHNOP_init_control:
case EVTCHNOP_expand_array:
case EVTCHNOP_set_priority:
/* We do not support FIFO channels at this point */
err = -ENOSYS;
break;
case EVTCHNOP_status: {
struct evtchn_status status;
qemu_build_assert(sizeof(status) == 24);
if (kvm_copy_from_gva(cs, arg, &status, sizeof(status))) {
err = -EFAULT;
break;
}
err = xen_evtchn_status_op(&status);
if (!err && kvm_copy_to_gva(cs, arg, &status, sizeof(status))) {
err = -EFAULT;
}
break;
}
case EVTCHNOP_close: {
struct evtchn_close close;
qemu_build_assert(sizeof(close) == 4);
if (kvm_copy_from_gva(cs, arg, &close, sizeof(close))) {
err = -EFAULT;
break;
}
err = xen_evtchn_close_op(&close);
break;
}
case EVTCHNOP_unmask: {
struct evtchn_unmask unmask;
qemu_build_assert(sizeof(unmask) == 4);
if (kvm_copy_from_gva(cs, arg, &unmask, sizeof(unmask))) {
err = -EFAULT;
break;
}
err = xen_evtchn_unmask_op(&unmask);
break;
}
case EVTCHNOP_bind_virq: {
struct evtchn_bind_virq virq;
qemu_build_assert(sizeof(virq) == 12);
if (kvm_copy_from_gva(cs, arg, &virq, sizeof(virq))) {
err = -EFAULT;
break;
}
err = xen_evtchn_bind_virq_op(&virq);
if (!err && kvm_copy_to_gva(cs, arg, &virq, sizeof(virq))) {
err = -EFAULT;
}
break;
}
case EVTCHNOP_bind_ipi: {
struct evtchn_bind_ipi ipi;
qemu_build_assert(sizeof(ipi) == 8);
if (kvm_copy_from_gva(cs, arg, &ipi, sizeof(ipi))) {
err = -EFAULT;
break;
}
err = xen_evtchn_bind_ipi_op(&ipi);
if (!err && kvm_copy_to_gva(cs, arg, &ipi, sizeof(ipi))) {
err = -EFAULT;
}
break;
}
case EVTCHNOP_send: {
struct evtchn_send send;
qemu_build_assert(sizeof(send) == 4);
if (kvm_copy_from_gva(cs, arg, &send, sizeof(send))) {
err = -EFAULT;
break;
}
err = xen_evtchn_send_op(&send);
break;
}
case EVTCHNOP_alloc_unbound: {
struct evtchn_alloc_unbound alloc;
qemu_build_assert(sizeof(alloc) == 8);
if (kvm_copy_from_gva(cs, arg, &alloc, sizeof(alloc))) {
err = -EFAULT;
break;
}
err = xen_evtchn_alloc_unbound_op(&alloc);
if (!err && kvm_copy_to_gva(cs, arg, &alloc, sizeof(alloc))) {
err = -EFAULT;
}
break;
}
case EVTCHNOP_bind_interdomain: {
struct evtchn_bind_interdomain interdomain;
qemu_build_assert(sizeof(interdomain) == 12);
if (kvm_copy_from_gva(cs, arg, &interdomain, sizeof(interdomain))) {
err = -EFAULT;
break;
}
err = xen_evtchn_bind_interdomain_op(&interdomain);
if (!err &&
kvm_copy_to_gva(cs, arg, &interdomain, sizeof(interdomain))) {
err = -EFAULT;
}
break;
}
case EVTCHNOP_bind_vcpu: {
struct evtchn_bind_vcpu vcpu;
qemu_build_assert(sizeof(vcpu) == 8);
if (kvm_copy_from_gva(cs, arg, &vcpu, sizeof(vcpu))) {
err = -EFAULT;
break;
}
err = xen_evtchn_bind_vcpu_op(&vcpu);
break;
}
case EVTCHNOP_reset: {
struct evtchn_reset reset;
qemu_build_assert(sizeof(reset) == 2);
if (kvm_copy_from_gva(cs, arg, &reset, sizeof(reset))) {
err = -EFAULT;
break;
}
err = xen_evtchn_reset_op(&reset);
break;
}
default:
return false;
}
exit->u.hcall.result = err;
return true;
}
int kvm_xen_soft_reset(void)
{
CPUState *cpu;
int err;
assert(qemu_mutex_iothread_locked());
trace_kvm_xen_soft_reset();
err = xen_evtchn_soft_reset();
if (err) {
return err;
}
/*
* Zero is the reset/startup state for HVM_PARAM_CALLBACK_IRQ. Strictly,
* it maps to HVM_PARAM_CALLBACK_TYPE_GSI with GSI#0, but Xen refuses to
* to deliver to the timer interrupt and treats that as 'disabled'.
*/
err = xen_evtchn_set_callback_param(0);
if (err) {
return err;
}
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;
}
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;
case SCHEDOP_poll:
/*
* Linux will panic if this doesn't work. Just yield; it's not
* worth overthinking it because with event channel handling
* in KVM, the kernel will intercept this and it will never
* reach QEMU anyway. The semantics of the hypercall explicltly
* permit spurious wakeups.
*/
case SCHEDOP_yield:
sched_yield();
err = 0;
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;
if (exit->u.hcall.cpl > 0) {
exit->u.hcall.result = -EPERM;
return true;
}
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_event_channel_op:
return kvm_xen_hcall_evtchn_op(exit, cpu, exit->u.hcall.params[0],
exit->u.hcall.params[1]);
case __HYPERVISOR_vcpu_op:
return kvm_xen_hcall_vcpu_op(exit, cpu,
exit->u.hcall.params[0],
exit->u.hcall.params[1],
exit->u.hcall.params[2]);
case __HYPERVISOR_hvm_op:
return kvm_xen_hcall_hvm_op(exit, cpu, exit->u.hcall.params[0],
exit->u.hcall.params[1]);
case __HYPERVISOR_memory_op:
return kvm_xen_hcall_memory_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]);
default:
return false;
}
}
int kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit)
{
if (exit->type != KVM_EXIT_XEN_HCALL) {
return -1;
}
/*
* The kernel latches the guest 32/64 mode when the MSR is used to fill
* the hypercall page. So if we see a hypercall in a mode that doesn't
* match our own idea of the guest mode, fetch the kernel's idea of the
* "long mode" to remain in sync.
*/
if (exit->u.hcall.longmode != xen_is_long_mode()) {
xen_sync_long_mode();
}
if (!do_kvm_xen_handle_exit(cpu, exit)) {
/*
* Some hypercalls will be deliberately "implemented" by returning
* -ENOSYS. This case is for hypercalls which are unexpected.
*/
exit->u.hcall.result = -ENOSYS;
qemu_log_mask(LOG_UNIMP, "Unimplemented Xen hypercall %"
PRId64 " (0x%" PRIx64 " 0x%" PRIx64 " 0x%" PRIx64 ")\n",
(uint64_t)exit->u.hcall.input,
(uint64_t)exit->u.hcall.params[0],
(uint64_t)exit->u.hcall.params[1],
(uint64_t)exit->u.hcall.params[2]);
}
trace_kvm_xen_hypercall(CPU(cpu)->cpu_index, exit->u.hcall.cpl,
exit->u.hcall.input, exit->u.hcall.params[0],
exit->u.hcall.params[1], exit->u.hcall.params[2],
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 = set_vcpu_info(cs, gpa);
if (ret < 0) {
return ret;
}
}
gpa = env->xen_vcpu_time_info_gpa;
if (gpa != INVALID_GPA) {
ret = kvm_xen_set_vcpu_attr(cs, KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO,
gpa);
if (ret < 0) {
return ret;
}
}
gpa = env->xen_vcpu_runstate_gpa;
if (gpa != INVALID_GPA) {
ret = kvm_xen_set_vcpu_attr(cs, KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR,
gpa);
if (ret < 0) {
return ret;
}
}
if (!kvm_xen_has_cap(EVTCHN_SEND)) {
return 0;
}
if (env->xen_vcpu_callback_vector) {
ret = kvm_xen_set_vcpu_callback_vector(cs);
if (ret < 0) {
return ret;
}
}
if (env->xen_virq[VIRQ_TIMER]) {
ret = kvm_xen_set_vcpu_timer(cs);
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;
int ret;
/*
* 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));
}
}
if (!kvm_xen_has_cap(EVTCHN_SEND)) {
return 0;
}
/*
* If the kernel is accelerating timers, read out the current value of the
* singleshot timer deadline.
*/
if (env->xen_virq[VIRQ_TIMER]) {
struct kvm_xen_vcpu_attr va = {
.type = KVM_XEN_VCPU_ATTR_TYPE_TIMER,
};
ret = kvm_vcpu_ioctl(cs, KVM_XEN_VCPU_GET_ATTR, &va);
if (ret < 0) {
return ret;
}
env->xen_singleshot_timer_ns = va.u.timer.expires_ns;
}
return 0;
}
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