xemu/hw/intc/spapr_xive_kvm.c

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/*
* QEMU PowerPC sPAPR XIVE interrupt controller model
*
* Copyright (c) 2017-2019, IBM Corporation.
*
* This code is licensed under the GPL version 2 or later. See the
* COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "qemu/log.h"
#include "qemu/error-report.h"
#include "qapi/error.h"
#include "target/ppc/cpu.h"
#include "sysemu/cpus.h"
#include "sysemu/kvm.h"
#include "sysemu/runstate.h"
#include "hw/ppc/spapr.h"
#include "hw/ppc/spapr_cpu_core.h"
#include "hw/ppc/spapr_xive.h"
#include "hw/ppc/xive.h"
#include "kvm_ppc.h"
#include "trace.h"
#include <sys/ioctl.h>
/*
* Helpers for CPU hotplug
*
* TODO: make a common KVMEnabledCPU layer for XICS and XIVE
*/
typedef struct KVMEnabledCPU {
unsigned long vcpu_id;
QLIST_ENTRY(KVMEnabledCPU) node;
} KVMEnabledCPU;
static QLIST_HEAD(, KVMEnabledCPU)
kvm_enabled_cpus = QLIST_HEAD_INITIALIZER(&kvm_enabled_cpus);
Revert series "spapr/xive: Allocate vCPU IPIs from the vCPU contexts" This series was largely built on the assumption that IPI numbers are numerically equal to vCPU ids. Even if this happens to be the case in practice with the default machine settings, this ceases to be true if VSMT is set to a different value than the number of vCPUs per core. This causes bogus IPI numbers to be created in KVM from a guest stand point. This leads to unknow results in the guest, including crashes or missing vCPUs (see BugLink) and even non-fatal oopses in current KVM that lacks a check before accessing misconfigured HW (see [1]). A tentative patch was sent (see [2]) but it seems too complex to be merged in an RC. Since the original changes are essentially an optimization, it seems safer to revert them for now. The damage is done by commit acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") but the previous patches in the series are really preparatory patches. So this reverts the whole series: eab0a2d06e97 ("spapr/xive: Allocate vCPU IPIs from the vCPU contexts") acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") fa94447a2cd6 ("spapr/xive: Use kvmppc_xive_source_reset() in post_load") 235d3b116213 ("spapr/xive: Modify kvm_cpu_is_enabled() interface") [1] https://marc.info/?l=kvm-ppc&m=160458409722959&w=4 [2] https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg03626.html Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Fixes: acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") BugLink: https://bugs.launchpad.net/qemu/+bug/1900241 Signed-off-by: Greg Kurz <groug@kaod.org> Acked-by: Cédric Le Goater <clg@kaod.org> Message-Id: <160554086275.1325084.12110142252189044646.stgit@bahia.lan>
2020-11-16 15:34:22 +00:00
static bool kvm_cpu_is_enabled(CPUState *cs)
{
KVMEnabledCPU *enabled_cpu;
Revert series "spapr/xive: Allocate vCPU IPIs from the vCPU contexts" This series was largely built on the assumption that IPI numbers are numerically equal to vCPU ids. Even if this happens to be the case in practice with the default machine settings, this ceases to be true if VSMT is set to a different value than the number of vCPUs per core. This causes bogus IPI numbers to be created in KVM from a guest stand point. This leads to unknow results in the guest, including crashes or missing vCPUs (see BugLink) and even non-fatal oopses in current KVM that lacks a check before accessing misconfigured HW (see [1]). A tentative patch was sent (see [2]) but it seems too complex to be merged in an RC. Since the original changes are essentially an optimization, it seems safer to revert them for now. The damage is done by commit acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") but the previous patches in the series are really preparatory patches. So this reverts the whole series: eab0a2d06e97 ("spapr/xive: Allocate vCPU IPIs from the vCPU contexts") acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") fa94447a2cd6 ("spapr/xive: Use kvmppc_xive_source_reset() in post_load") 235d3b116213 ("spapr/xive: Modify kvm_cpu_is_enabled() interface") [1] https://marc.info/?l=kvm-ppc&m=160458409722959&w=4 [2] https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg03626.html Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Fixes: acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") BugLink: https://bugs.launchpad.net/qemu/+bug/1900241 Signed-off-by: Greg Kurz <groug@kaod.org> Acked-by: Cédric Le Goater <clg@kaod.org> Message-Id: <160554086275.1325084.12110142252189044646.stgit@bahia.lan>
2020-11-16 15:34:22 +00:00
unsigned long vcpu_id = kvm_arch_vcpu_id(cs);
QLIST_FOREACH(enabled_cpu, &kvm_enabled_cpus, node) {
if (enabled_cpu->vcpu_id == vcpu_id) {
return true;
}
}
return false;
}
static void kvm_cpu_enable(CPUState *cs)
{
KVMEnabledCPU *enabled_cpu;
unsigned long vcpu_id = kvm_arch_vcpu_id(cs);
enabled_cpu = g_malloc(sizeof(*enabled_cpu));
enabled_cpu->vcpu_id = vcpu_id;
QLIST_INSERT_HEAD(&kvm_enabled_cpus, enabled_cpu, node);
}
static void kvm_cpu_disable_all(void)
{
KVMEnabledCPU *enabled_cpu, *next;
QLIST_FOREACH_SAFE(enabled_cpu, &kvm_enabled_cpus, node, next) {
QLIST_REMOVE(enabled_cpu, node);
g_free(enabled_cpu);
}
}
/*
* XIVE Thread Interrupt Management context (KVM)
*/
int kvmppc_xive_cpu_set_state(XiveTCTX *tctx, Error **errp)
{
SpaprXive *xive = SPAPR_XIVE(tctx->xptr);
uint64_t state[2];
int ret;
assert(xive->fd != -1);
/* word0 and word1 of the OS ring. */
state[0] = *((uint64_t *) &tctx->regs[TM_QW1_OS]);
ret = kvm_set_one_reg(tctx->cs, KVM_REG_PPC_VP_STATE, state);
if (ret != 0) {
error_setg_errno(errp, -ret,
"XIVE: could not restore KVM state of CPU %ld",
kvm_arch_vcpu_id(tctx->cs));
return ret;
}
return 0;
}
int kvmppc_xive_cpu_get_state(XiveTCTX *tctx, Error **errp)
{
SpaprXive *xive = SPAPR_XIVE(tctx->xptr);
uint64_t state[2] = { 0 };
int ret;
assert(xive->fd != -1);
ret = kvm_get_one_reg(tctx->cs, KVM_REG_PPC_VP_STATE, state);
if (ret != 0) {
error_setg_errno(errp, -ret,
"XIVE: could not capture KVM state of CPU %ld",
kvm_arch_vcpu_id(tctx->cs));
return ret;
}
/* word0 and word1 of the OS ring. */
*((uint64_t *) &tctx->regs[TM_QW1_OS]) = state[0];
return 0;
}
typedef struct {
XiveTCTX *tctx;
Error **errp;
int ret;
} XiveCpuGetState;
static void kvmppc_xive_cpu_do_synchronize_state(CPUState *cpu,
run_on_cpu_data arg)
{
XiveCpuGetState *s = arg.host_ptr;
s->ret = kvmppc_xive_cpu_get_state(s->tctx, s->errp);
}
int kvmppc_xive_cpu_synchronize_state(XiveTCTX *tctx, Error **errp)
{
XiveCpuGetState s = {
.tctx = tctx,
.errp = errp,
};
/*
* Kick the vCPU to make sure they are available for the KVM ioctl.
*/
run_on_cpu(tctx->cs, kvmppc_xive_cpu_do_synchronize_state,
RUN_ON_CPU_HOST_PTR(&s));
return s.ret;
}
int kvmppc_xive_cpu_connect(XiveTCTX *tctx, Error **errp)
{
ERRP_GUARD();
SpaprXive *xive = SPAPR_XIVE(tctx->xptr);
unsigned long vcpu_id;
int ret;
assert(xive->fd != -1);
/* Check if CPU was hot unplugged and replugged. */
Revert series "spapr/xive: Allocate vCPU IPIs from the vCPU contexts" This series was largely built on the assumption that IPI numbers are numerically equal to vCPU ids. Even if this happens to be the case in practice with the default machine settings, this ceases to be true if VSMT is set to a different value than the number of vCPUs per core. This causes bogus IPI numbers to be created in KVM from a guest stand point. This leads to unknow results in the guest, including crashes or missing vCPUs (see BugLink) and even non-fatal oopses in current KVM that lacks a check before accessing misconfigured HW (see [1]). A tentative patch was sent (see [2]) but it seems too complex to be merged in an RC. Since the original changes are essentially an optimization, it seems safer to revert them for now. The damage is done by commit acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") but the previous patches in the series are really preparatory patches. So this reverts the whole series: eab0a2d06e97 ("spapr/xive: Allocate vCPU IPIs from the vCPU contexts") acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") fa94447a2cd6 ("spapr/xive: Use kvmppc_xive_source_reset() in post_load") 235d3b116213 ("spapr/xive: Modify kvm_cpu_is_enabled() interface") [1] https://marc.info/?l=kvm-ppc&m=160458409722959&w=4 [2] https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg03626.html Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Fixes: acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") BugLink: https://bugs.launchpad.net/qemu/+bug/1900241 Signed-off-by: Greg Kurz <groug@kaod.org> Acked-by: Cédric Le Goater <clg@kaod.org> Message-Id: <160554086275.1325084.12110142252189044646.stgit@bahia.lan>
2020-11-16 15:34:22 +00:00
if (kvm_cpu_is_enabled(tctx->cs)) {
return 0;
}
vcpu_id = kvm_arch_vcpu_id(tctx->cs);
trace_kvm_xive_cpu_connect(vcpu_id);
ret = kvm_vcpu_enable_cap(tctx->cs, KVM_CAP_PPC_IRQ_XIVE, 0, xive->fd,
vcpu_id, 0);
if (ret < 0) {
error_setg_errno(errp, -ret,
"XIVE: unable to connect CPU%ld to KVM device",
vcpu_id);
if (ret == -ENOSPC) {
error_append_hint(errp, "Try -smp maxcpus=N with N < %u\n",
MACHINE(qdev_get_machine())->smp.max_cpus);
}
return ret;
}
kvm_cpu_enable(tctx->cs);
return 0;
}
/*
* XIVE Interrupt Source (KVM)
*/
int kvmppc_xive_set_source_config(SpaprXive *xive, uint32_t lisn, XiveEAS *eas,
Error **errp)
{
uint32_t end_idx;
uint32_t end_blk;
uint8_t priority;
uint32_t server;
bool masked;
uint32_t eisn;
uint64_t kvm_src;
assert(xive_eas_is_valid(eas));
end_idx = xive_get_field64(EAS_END_INDEX, eas->w);
end_blk = xive_get_field64(EAS_END_BLOCK, eas->w);
eisn = xive_get_field64(EAS_END_DATA, eas->w);
masked = xive_eas_is_masked(eas);
spapr_xive_end_to_target(end_blk, end_idx, &server, &priority);
kvm_src = priority << KVM_XIVE_SOURCE_PRIORITY_SHIFT &
KVM_XIVE_SOURCE_PRIORITY_MASK;
kvm_src |= server << KVM_XIVE_SOURCE_SERVER_SHIFT &
KVM_XIVE_SOURCE_SERVER_MASK;
kvm_src |= ((uint64_t) masked << KVM_XIVE_SOURCE_MASKED_SHIFT) &
KVM_XIVE_SOURCE_MASKED_MASK;
kvm_src |= ((uint64_t)eisn << KVM_XIVE_SOURCE_EISN_SHIFT) &
KVM_XIVE_SOURCE_EISN_MASK;
return kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_SOURCE_CONFIG, lisn,
&kvm_src, true, errp);
}
void kvmppc_xive_sync_source(SpaprXive *xive, uint32_t lisn, Error **errp)
{
kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_SOURCE_SYNC, lisn,
NULL, true, errp);
}
/*
* At reset, the interrupt sources are simply created and MASKED. We
* only need to inform the KVM XIVE device about their type: LSI or
* MSI.
*/
int kvmppc_xive_source_reset_one(XiveSource *xsrc, int srcno, Error **errp)
{
SpaprXive *xive = SPAPR_XIVE(xsrc->xive);
uint64_t state = 0;
assert(xive->fd != -1);
if (xive_source_irq_is_lsi(xsrc, srcno)) {
state |= KVM_XIVE_LEVEL_SENSITIVE;
if (xsrc->status[srcno] & XIVE_STATUS_ASSERTED) {
state |= KVM_XIVE_LEVEL_ASSERTED;
}
}
return kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_SOURCE, srcno, &state,
true, errp);
}
static int kvmppc_xive_source_reset(XiveSource *xsrc, Error **errp)
{
SpaprXive *xive = SPAPR_XIVE(xsrc->xive);
int i;
Revert series "spapr/xive: Allocate vCPU IPIs from the vCPU contexts" This series was largely built on the assumption that IPI numbers are numerically equal to vCPU ids. Even if this happens to be the case in practice with the default machine settings, this ceases to be true if VSMT is set to a different value than the number of vCPUs per core. This causes bogus IPI numbers to be created in KVM from a guest stand point. This leads to unknow results in the guest, including crashes or missing vCPUs (see BugLink) and even non-fatal oopses in current KVM that lacks a check before accessing misconfigured HW (see [1]). A tentative patch was sent (see [2]) but it seems too complex to be merged in an RC. Since the original changes are essentially an optimization, it seems safer to revert them for now. The damage is done by commit acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") but the previous patches in the series are really preparatory patches. So this reverts the whole series: eab0a2d06e97 ("spapr/xive: Allocate vCPU IPIs from the vCPU contexts") acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") fa94447a2cd6 ("spapr/xive: Use kvmppc_xive_source_reset() in post_load") 235d3b116213 ("spapr/xive: Modify kvm_cpu_is_enabled() interface") [1] https://marc.info/?l=kvm-ppc&m=160458409722959&w=4 [2] https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg03626.html Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Fixes: acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") BugLink: https://bugs.launchpad.net/qemu/+bug/1900241 Signed-off-by: Greg Kurz <groug@kaod.org> Acked-by: Cédric Le Goater <clg@kaod.org> Message-Id: <160554086275.1325084.12110142252189044646.stgit@bahia.lan>
2020-11-16 15:34:22 +00:00
for (i = 0; i < xsrc->nr_irqs; i++) {
int ret;
if (!xive_eas_is_valid(&xive->eat[i])) {
continue;
}
ret = kvmppc_xive_source_reset_one(xsrc, i, errp);
if (ret < 0) {
return ret;
}
}
return 0;
}
/*
* This is used to perform the magic loads on the ESB pages, described
* in xive.h.
*
* Memory barriers should not be needed for loads (no store for now).
*/
static uint64_t xive_esb_rw(XiveSource *xsrc, int srcno, uint32_t offset,
uint64_t data, bool write)
{
uint64_t *addr = xsrc->esb_mmap + xive_source_esb_mgmt(xsrc, srcno) +
offset;
if (write) {
*addr = cpu_to_be64(data);
return -1;
} else {
/* Prevent the compiler from optimizing away the load */
volatile uint64_t value = be64_to_cpu(*addr);
return value;
}
}
static uint8_t xive_esb_read(XiveSource *xsrc, int srcno, uint32_t offset)
{
return xive_esb_rw(xsrc, srcno, offset, 0, 0) & 0x3;
}
static void xive_esb_trigger(XiveSource *xsrc, int srcno)
{
uint64_t *addr = xsrc->esb_mmap + xive_source_esb_page(xsrc, srcno);
*addr = 0x0;
}
uint64_t kvmppc_xive_esb_rw(XiveSource *xsrc, int srcno, uint32_t offset,
uint64_t data, bool write)
{
if (write) {
return xive_esb_rw(xsrc, srcno, offset, data, 1);
}
trace_kvm_xive_source_reset(srcno);
/*
* Special Load EOI handling for LSI sources. Q bit is never set
* and the interrupt should be re-triggered if the level is still
* asserted.
*/
if (xive_source_irq_is_lsi(xsrc, srcno) &&
offset == XIVE_ESB_LOAD_EOI) {
xive_esb_read(xsrc, srcno, XIVE_ESB_SET_PQ_00);
if (xsrc->status[srcno] & XIVE_STATUS_ASSERTED) {
xive_esb_trigger(xsrc, srcno);
}
return 0;
} else {
return xive_esb_rw(xsrc, srcno, offset, 0, 0);
}
}
static void kvmppc_xive_source_get_state(XiveSource *xsrc)
{
SpaprXive *xive = SPAPR_XIVE(xsrc->xive);
int i;
for (i = 0; i < xsrc->nr_irqs; i++) {
uint8_t pq;
Revert series "spapr/xive: Allocate vCPU IPIs from the vCPU contexts" This series was largely built on the assumption that IPI numbers are numerically equal to vCPU ids. Even if this happens to be the case in practice with the default machine settings, this ceases to be true if VSMT is set to a different value than the number of vCPUs per core. This causes bogus IPI numbers to be created in KVM from a guest stand point. This leads to unknow results in the guest, including crashes or missing vCPUs (see BugLink) and even non-fatal oopses in current KVM that lacks a check before accessing misconfigured HW (see [1]). A tentative patch was sent (see [2]) but it seems too complex to be merged in an RC. Since the original changes are essentially an optimization, it seems safer to revert them for now. The damage is done by commit acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") but the previous patches in the series are really preparatory patches. So this reverts the whole series: eab0a2d06e97 ("spapr/xive: Allocate vCPU IPIs from the vCPU contexts") acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") fa94447a2cd6 ("spapr/xive: Use kvmppc_xive_source_reset() in post_load") 235d3b116213 ("spapr/xive: Modify kvm_cpu_is_enabled() interface") [1] https://marc.info/?l=kvm-ppc&m=160458409722959&w=4 [2] https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg03626.html Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Fixes: acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") BugLink: https://bugs.launchpad.net/qemu/+bug/1900241 Signed-off-by: Greg Kurz <groug@kaod.org> Acked-by: Cédric Le Goater <clg@kaod.org> Message-Id: <160554086275.1325084.12110142252189044646.stgit@bahia.lan>
2020-11-16 15:34:22 +00:00
if (!xive_eas_is_valid(&xive->eat[i])) {
continue;
}
/* Perform a load without side effect to retrieve the PQ bits */
pq = xive_esb_read(xsrc, i, XIVE_ESB_GET);
/* and save PQ locally */
xive_source_esb_set(xsrc, i, pq);
}
}
void kvmppc_xive_source_set_irq(void *opaque, int srcno, int val)
{
XiveSource *xsrc = opaque;
if (!xive_source_irq_is_lsi(xsrc, srcno)) {
if (!val) {
return;
}
} else {
if (val) {
xsrc->status[srcno] |= XIVE_STATUS_ASSERTED;
} else {
xsrc->status[srcno] &= ~XIVE_STATUS_ASSERTED;
}
}
xive_esb_trigger(xsrc, srcno);
}
/*
* sPAPR XIVE interrupt controller (KVM)
*/
int kvmppc_xive_get_queue_config(SpaprXive *xive, uint8_t end_blk,
uint32_t end_idx, XiveEND *end,
Error **errp)
{
struct kvm_ppc_xive_eq kvm_eq = { 0 };
uint64_t kvm_eq_idx;
uint8_t priority;
uint32_t server;
int ret;
assert(xive_end_is_valid(end));
/* Encode the tuple (server, prio) as a KVM EQ index */
spapr_xive_end_to_target(end_blk, end_idx, &server, &priority);
kvm_eq_idx = priority << KVM_XIVE_EQ_PRIORITY_SHIFT &
KVM_XIVE_EQ_PRIORITY_MASK;
kvm_eq_idx |= server << KVM_XIVE_EQ_SERVER_SHIFT &
KVM_XIVE_EQ_SERVER_MASK;
ret = kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_EQ_CONFIG, kvm_eq_idx,
&kvm_eq, false, errp);
if (ret < 0) {
return ret;
}
/*
* The EQ index and toggle bit are updated by HW. These are the
* only fields from KVM we want to update QEMU with. The other END
* fields should already be in the QEMU END table.
*/
end->w1 = xive_set_field32(END_W1_GENERATION, 0ul, kvm_eq.qtoggle) |
xive_set_field32(END_W1_PAGE_OFF, 0ul, kvm_eq.qindex);
return 0;
}
int kvmppc_xive_set_queue_config(SpaprXive *xive, uint8_t end_blk,
uint32_t end_idx, XiveEND *end,
Error **errp)
{
struct kvm_ppc_xive_eq kvm_eq = { 0 };
uint64_t kvm_eq_idx;
uint8_t priority;
uint32_t server;
/*
* Build the KVM state from the local END structure.
*/
kvm_eq.flags = 0;
if (xive_get_field32(END_W0_UCOND_NOTIFY, end->w0)) {
kvm_eq.flags |= KVM_XIVE_EQ_ALWAYS_NOTIFY;
}
/*
* If the hcall is disabling the EQ, set the size and page address
* to zero. When migrating, only valid ENDs are taken into
* account.
*/
if (xive_end_is_valid(end)) {
kvm_eq.qshift = xive_get_field32(END_W0_QSIZE, end->w0) + 12;
kvm_eq.qaddr = xive_end_qaddr(end);
/*
* The EQ toggle bit and index should only be relevant when
* restoring the EQ state
*/
kvm_eq.qtoggle = xive_get_field32(END_W1_GENERATION, end->w1);
kvm_eq.qindex = xive_get_field32(END_W1_PAGE_OFF, end->w1);
} else {
kvm_eq.qshift = 0;
kvm_eq.qaddr = 0;
}
/* Encode the tuple (server, prio) as a KVM EQ index */
spapr_xive_end_to_target(end_blk, end_idx, &server, &priority);
kvm_eq_idx = priority << KVM_XIVE_EQ_PRIORITY_SHIFT &
KVM_XIVE_EQ_PRIORITY_MASK;
kvm_eq_idx |= server << KVM_XIVE_EQ_SERVER_SHIFT &
KVM_XIVE_EQ_SERVER_MASK;
return
kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_EQ_CONFIG, kvm_eq_idx,
&kvm_eq, true, errp);
}
void kvmppc_xive_reset(SpaprXive *xive, Error **errp)
{
kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_CTRL, KVM_DEV_XIVE_RESET,
NULL, true, errp);
}
static int kvmppc_xive_get_queues(SpaprXive *xive, Error **errp)
{
int i;
int ret;
for (i = 0; i < xive->nr_ends; i++) {
if (!xive_end_is_valid(&xive->endt[i])) {
continue;
}
ret = kvmppc_xive_get_queue_config(xive, SPAPR_XIVE_BLOCK_ID, i,
&xive->endt[i], errp);
if (ret < 0) {
return ret;
}
}
return 0;
}
/*
* The primary goal of the XIVE VM change handler is to mark the EQ
* pages dirty when all XIVE event notifications have stopped.
*
* Whenever the VM is stopped, the VM change handler sets the source
* PQs to PENDING to stop the flow of events and to possibly catch a
* triggered interrupt occuring while the VM is stopped. The previous
* state is saved in anticipation of a migration. The XIVE controller
* is then synced through KVM to flush any in-flight event
* notification and stabilize the EQs.
*
* At this stage, we can mark the EQ page dirty and let a migration
* sequence transfer the EQ pages to the destination, which is done
* just after the stop state.
*
* The previous configuration of the sources is restored when the VM
* runs again. If an interrupt was queued while the VM was stopped,
* simply generate a trigger.
*/
static void kvmppc_xive_change_state_handler(void *opaque, int running,
RunState state)
{
SpaprXive *xive = opaque;
XiveSource *xsrc = &xive->source;
Error *local_err = NULL;
int i;
/*
* Restore the sources to their initial state. This is called when
* the VM resumes after a stop or a migration.
*/
if (running) {
for (i = 0; i < xsrc->nr_irqs; i++) {
uint8_t pq;
uint8_t old_pq;
Revert series "spapr/xive: Allocate vCPU IPIs from the vCPU contexts" This series was largely built on the assumption that IPI numbers are numerically equal to vCPU ids. Even if this happens to be the case in practice with the default machine settings, this ceases to be true if VSMT is set to a different value than the number of vCPUs per core. This causes bogus IPI numbers to be created in KVM from a guest stand point. This leads to unknow results in the guest, including crashes or missing vCPUs (see BugLink) and even non-fatal oopses in current KVM that lacks a check before accessing misconfigured HW (see [1]). A tentative patch was sent (see [2]) but it seems too complex to be merged in an RC. Since the original changes are essentially an optimization, it seems safer to revert them for now. The damage is done by commit acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") but the previous patches in the series are really preparatory patches. So this reverts the whole series: eab0a2d06e97 ("spapr/xive: Allocate vCPU IPIs from the vCPU contexts") acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") fa94447a2cd6 ("spapr/xive: Use kvmppc_xive_source_reset() in post_load") 235d3b116213 ("spapr/xive: Modify kvm_cpu_is_enabled() interface") [1] https://marc.info/?l=kvm-ppc&m=160458409722959&w=4 [2] https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg03626.html Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Fixes: acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") BugLink: https://bugs.launchpad.net/qemu/+bug/1900241 Signed-off-by: Greg Kurz <groug@kaod.org> Acked-by: Cédric Le Goater <clg@kaod.org> Message-Id: <160554086275.1325084.12110142252189044646.stgit@bahia.lan>
2020-11-16 15:34:22 +00:00
if (!xive_eas_is_valid(&xive->eat[i])) {
continue;
}
pq = xive_source_esb_get(xsrc, i);
old_pq = xive_esb_read(xsrc, i, XIVE_ESB_SET_PQ_00 + (pq << 8));
/*
* An interrupt was queued while the VM was stopped,
* generate a trigger.
*/
if (pq == XIVE_ESB_RESET && old_pq == XIVE_ESB_QUEUED) {
xive_esb_trigger(xsrc, i);
}
}
return;
}
/*
* Mask the sources, to stop the flow of event notifications, and
* save the PQs locally in the XiveSource object. The XiveSource
* state will be collected later on by its vmstate handler if a
* migration is in progress.
*/
for (i = 0; i < xsrc->nr_irqs; i++) {
uint8_t pq;
Revert series "spapr/xive: Allocate vCPU IPIs from the vCPU contexts" This series was largely built on the assumption that IPI numbers are numerically equal to vCPU ids. Even if this happens to be the case in practice with the default machine settings, this ceases to be true if VSMT is set to a different value than the number of vCPUs per core. This causes bogus IPI numbers to be created in KVM from a guest stand point. This leads to unknow results in the guest, including crashes or missing vCPUs (see BugLink) and even non-fatal oopses in current KVM that lacks a check before accessing misconfigured HW (see [1]). A tentative patch was sent (see [2]) but it seems too complex to be merged in an RC. Since the original changes are essentially an optimization, it seems safer to revert them for now. The damage is done by commit acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") but the previous patches in the series are really preparatory patches. So this reverts the whole series: eab0a2d06e97 ("spapr/xive: Allocate vCPU IPIs from the vCPU contexts") acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") fa94447a2cd6 ("spapr/xive: Use kvmppc_xive_source_reset() in post_load") 235d3b116213 ("spapr/xive: Modify kvm_cpu_is_enabled() interface") [1] https://marc.info/?l=kvm-ppc&m=160458409722959&w=4 [2] https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg03626.html Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Fixes: acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") BugLink: https://bugs.launchpad.net/qemu/+bug/1900241 Signed-off-by: Greg Kurz <groug@kaod.org> Acked-by: Cédric Le Goater <clg@kaod.org> Message-Id: <160554086275.1325084.12110142252189044646.stgit@bahia.lan>
2020-11-16 15:34:22 +00:00
if (!xive_eas_is_valid(&xive->eat[i])) {
continue;
}
pq = xive_esb_read(xsrc, i, XIVE_ESB_GET);
/*
* PQ is set to PENDING to possibly catch a triggered
* interrupt occuring while the VM is stopped (hotplug event
* for instance) .
*/
if (pq != XIVE_ESB_OFF) {
pq = xive_esb_read(xsrc, i, XIVE_ESB_SET_PQ_10);
}
xive_source_esb_set(xsrc, i, pq);
}
/*
* Sync the XIVE controller in KVM, to flush in-flight event
* notification that should be enqueued in the EQs and mark the
* XIVE EQ pages dirty to collect all updates.
*/
kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_CTRL,
KVM_DEV_XIVE_EQ_SYNC, NULL, true, &local_err);
if (local_err) {
error_report_err(local_err);
return;
}
}
void kvmppc_xive_synchronize_state(SpaprXive *xive, Error **errp)
{
assert(xive->fd != -1);
/*
* When the VM is stopped, the sources are masked and the previous
* state is saved in anticipation of a migration. We should not
* synchronize the source state in that case else we will override
* the saved state.
*/
if (runstate_is_running()) {
kvmppc_xive_source_get_state(&xive->source);
}
/* EAT: there is no extra state to query from KVM */
/* ENDT */
kvmppc_xive_get_queues(xive, errp);
}
/*
* The SpaprXive 'pre_save' method is called by the vmstate handler of
* the SpaprXive model, after the XIVE controller is synced in the VM
* change handler.
*/
int kvmppc_xive_pre_save(SpaprXive *xive)
{
Error *local_err = NULL;
int ret;
assert(xive->fd != -1);
/* EAT: there is no extra state to query from KVM */
/* ENDT */
ret = kvmppc_xive_get_queues(xive, &local_err);
if (ret < 0) {
error_report_err(local_err);
return ret;
}
return 0;
}
/*
* The SpaprXive 'post_load' method is not called by a vmstate
* handler. It is called at the sPAPR machine level at the end of the
* migration sequence by the sPAPR IRQ backend 'post_load' method,
* when all XIVE states have been transferred and loaded.
*/
int kvmppc_xive_post_load(SpaprXive *xive, int version_id)
{
Error *local_err = NULL;
CPUState *cs;
int i;
int ret;
/* The KVM XIVE device should be in use */
assert(xive->fd != -1);
/* Restore the ENDT first. The targetting depends on it. */
for (i = 0; i < xive->nr_ends; i++) {
if (!xive_end_is_valid(&xive->endt[i])) {
continue;
}
ret = kvmppc_xive_set_queue_config(xive, SPAPR_XIVE_BLOCK_ID, i,
&xive->endt[i], &local_err);
if (ret < 0) {
goto fail;
}
}
/* Restore the EAT */
for (i = 0; i < xive->nr_irqs; i++) {
Revert series "spapr/xive: Allocate vCPU IPIs from the vCPU contexts" This series was largely built on the assumption that IPI numbers are numerically equal to vCPU ids. Even if this happens to be the case in practice with the default machine settings, this ceases to be true if VSMT is set to a different value than the number of vCPUs per core. This causes bogus IPI numbers to be created in KVM from a guest stand point. This leads to unknow results in the guest, including crashes or missing vCPUs (see BugLink) and even non-fatal oopses in current KVM that lacks a check before accessing misconfigured HW (see [1]). A tentative patch was sent (see [2]) but it seems too complex to be merged in an RC. Since the original changes are essentially an optimization, it seems safer to revert them for now. The damage is done by commit acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") but the previous patches in the series are really preparatory patches. So this reverts the whole series: eab0a2d06e97 ("spapr/xive: Allocate vCPU IPIs from the vCPU contexts") acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") fa94447a2cd6 ("spapr/xive: Use kvmppc_xive_source_reset() in post_load") 235d3b116213 ("spapr/xive: Modify kvm_cpu_is_enabled() interface") [1] https://marc.info/?l=kvm-ppc&m=160458409722959&w=4 [2] https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg03626.html Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Fixes: acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") BugLink: https://bugs.launchpad.net/qemu/+bug/1900241 Signed-off-by: Greg Kurz <groug@kaod.org> Acked-by: Cédric Le Goater <clg@kaod.org> Message-Id: <160554086275.1325084.12110142252189044646.stgit@bahia.lan>
2020-11-16 15:34:22 +00:00
if (!xive_eas_is_valid(&xive->eat[i])) {
continue;
}
Revert series "spapr/xive: Allocate vCPU IPIs from the vCPU contexts" This series was largely built on the assumption that IPI numbers are numerically equal to vCPU ids. Even if this happens to be the case in practice with the default machine settings, this ceases to be true if VSMT is set to a different value than the number of vCPUs per core. This causes bogus IPI numbers to be created in KVM from a guest stand point. This leads to unknow results in the guest, including crashes or missing vCPUs (see BugLink) and even non-fatal oopses in current KVM that lacks a check before accessing misconfigured HW (see [1]). A tentative patch was sent (see [2]) but it seems too complex to be merged in an RC. Since the original changes are essentially an optimization, it seems safer to revert them for now. The damage is done by commit acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") but the previous patches in the series are really preparatory patches. So this reverts the whole series: eab0a2d06e97 ("spapr/xive: Allocate vCPU IPIs from the vCPU contexts") acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") fa94447a2cd6 ("spapr/xive: Use kvmppc_xive_source_reset() in post_load") 235d3b116213 ("spapr/xive: Modify kvm_cpu_is_enabled() interface") [1] https://marc.info/?l=kvm-ppc&m=160458409722959&w=4 [2] https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg03626.html Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Fixes: acbdb9956fe9 ("spapr/xive: Allocate IPIs independently from the other sources") BugLink: https://bugs.launchpad.net/qemu/+bug/1900241 Signed-off-by: Greg Kurz <groug@kaod.org> Acked-by: Cédric Le Goater <clg@kaod.org> Message-Id: <160554086275.1325084.12110142252189044646.stgit@bahia.lan>
2020-11-16 15:34:22 +00:00
/*
* We can only restore the source config if the source has been
* previously set in KVM. Since we don't do that for all interrupts
* at reset time anymore, let's do it now.
*/
ret = kvmppc_xive_source_reset_one(&xive->source, i, &local_err);
if (ret < 0) {
goto fail;
}
ret = kvmppc_xive_set_source_config(xive, i, &xive->eat[i], &local_err);
if (ret < 0) {
goto fail;
}
}
/*
* Restore the thread interrupt contexts of initial CPUs.
*
* The context of hotplugged CPUs is restored later, by the
* 'post_load' handler of the XiveTCTX model because they are not
* available at the time the SpaprXive 'post_load' method is
* called. We can not restore the context of all CPUs in the
* 'post_load' handler of XiveTCTX because the machine is not
* necessarily connected to the KVM device at that time.
*/
CPU_FOREACH(cs) {
PowerPCCPU *cpu = POWERPC_CPU(cs);
ret = kvmppc_xive_cpu_set_state(spapr_cpu_state(cpu)->tctx, &local_err);
if (ret < 0) {
goto fail;
}
}
/* The source states will be restored when the machine starts running */
return 0;
fail:
error_report_err(local_err);
return ret;
}
/* Returns MAP_FAILED on error and sets errno */
static void *kvmppc_xive_mmap(SpaprXive *xive, int pgoff, size_t len,
Error **errp)
{
void *addr;
uint32_t page_shift = 16; /* TODO: fix page_shift */
addr = mmap(NULL, len, PROT_WRITE | PROT_READ, MAP_SHARED, xive->fd,
pgoff << page_shift);
if (addr == MAP_FAILED) {
error_setg_errno(errp, errno, "XIVE: unable to set memory mapping");
}
return addr;
}
/*
* All the XIVE memory regions are now backed by mappings from the KVM
* XIVE device.
*/
int kvmppc_xive_connect(SpaprInterruptController *intc, uint32_t nr_servers,
Error **errp)
{
SpaprXive *xive = SPAPR_XIVE(intc);
XiveSource *xsrc = &xive->source;
size_t esb_len = xive_source_esb_len(xsrc);
size_t tima_len = 4ull << TM_SHIFT;
CPUState *cs;
int fd;
void *addr;
int ret;
/*
* The KVM XIVE device already in use. This is the case when
* rebooting under the XIVE-only interrupt mode.
*/
if (xive->fd != -1) {
return 0;
}
if (!kvmppc_has_cap_xive()) {
error_setg(errp, "IRQ_XIVE capability must be present for KVM");
return -1;
}
/* First, create the KVM XIVE device */
fd = kvm_create_device(kvm_state, KVM_DEV_TYPE_XIVE, false);
if (fd < 0) {
error_setg_errno(errp, -fd, "XIVE: error creating KVM device");
return -1;
}
xive->fd = fd;
/* Tell KVM about the # of VCPUs we may have */
if (kvm_device_check_attr(xive->fd, KVM_DEV_XIVE_GRP_CTRL,
KVM_DEV_XIVE_NR_SERVERS)) {
ret = kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_CTRL,
KVM_DEV_XIVE_NR_SERVERS, &nr_servers, true,
errp);
if (ret < 0) {
goto fail;
}
}
/*
* 1. Source ESB pages - KVM mapping
*/
addr = kvmppc_xive_mmap(xive, KVM_XIVE_ESB_PAGE_OFFSET, esb_len, errp);
if (addr == MAP_FAILED) {
goto fail;
}
xsrc->esb_mmap = addr;
memory_region_init_ram_device_ptr(&xsrc->esb_mmio_kvm, OBJECT(xsrc),
"xive.esb-kvm", esb_len, xsrc->esb_mmap);
memory_region_add_subregion_overlap(&xsrc->esb_mmio, 0,
&xsrc->esb_mmio_kvm, 1);
/*
* 2. END ESB pages (No KVM support yet)
*/
/*
* 3. TIMA pages - KVM mapping
*/
addr = kvmppc_xive_mmap(xive, KVM_XIVE_TIMA_PAGE_OFFSET, tima_len, errp);
if (addr == MAP_FAILED) {
goto fail;
}
xive->tm_mmap = addr;
memory_region_init_ram_device_ptr(&xive->tm_mmio_kvm, OBJECT(xive),
"xive.tima", tima_len, xive->tm_mmap);
memory_region_add_subregion_overlap(&xive->tm_mmio, 0,
&xive->tm_mmio_kvm, 1);
xive->change = qemu_add_vm_change_state_handler(
kvmppc_xive_change_state_handler, xive);
/* Connect the presenters to the initial VCPUs of the machine */
CPU_FOREACH(cs) {
PowerPCCPU *cpu = POWERPC_CPU(cs);
ret = kvmppc_xive_cpu_connect(spapr_cpu_state(cpu)->tctx, errp);
if (ret < 0) {
goto fail;
}
}
/* Update the KVM sources */
ret = kvmppc_xive_source_reset(xsrc, errp);
if (ret < 0) {
goto fail;
}
kvm_kernel_irqchip = true;
kvm_msi_via_irqfd_allowed = true;
kvm_gsi_direct_mapping = true;
return 0;
fail:
kvmppc_xive_disconnect(intc);
return -1;
}
void kvmppc_xive_disconnect(SpaprInterruptController *intc)
{
SpaprXive *xive = SPAPR_XIVE(intc);
XiveSource *xsrc;
size_t esb_len;
assert(xive->fd != -1);
/* Clear the KVM mapping */
xsrc = &xive->source;
esb_len = xive_source_esb_len(xsrc);
if (xsrc->esb_mmap) {
memory_region_del_subregion(&xsrc->esb_mmio, &xsrc->esb_mmio_kvm);
object_unparent(OBJECT(&xsrc->esb_mmio_kvm));
munmap(xsrc->esb_mmap, esb_len);
xsrc->esb_mmap = NULL;
}
if (xive->tm_mmap) {
memory_region_del_subregion(&xive->tm_mmio, &xive->tm_mmio_kvm);
object_unparent(OBJECT(&xive->tm_mmio_kvm));
munmap(xive->tm_mmap, 4ull << TM_SHIFT);
xive->tm_mmap = NULL;
}
/*
* When the KVM device fd is closed, the KVM device is destroyed
* and removed from the list of devices of the VM. The VCPU
* presenters are also detached from the device.
*/
close(xive->fd);
xive->fd = -1;
kvm_kernel_irqchip = false;
kvm_msi_via_irqfd_allowed = false;
kvm_gsi_direct_mapping = false;
/* Clear the local list of presenter (hotplug) */
kvm_cpu_disable_all();
/* VM Change state handler is not needed anymore */
if (xive->change) {
qemu_del_vm_change_state_handler(xive->change);
xive->change = NULL;
}
}