spapr/xive: add hcall support when under KVM

XIVE hcalls are all redirected to QEMU as none are on a fast path.
When necessary, QEMU invokes KVM through specific ioctls to perform
host operations. QEMU should have done the necessary checks before
calling KVM and, in case of failure, H_HARDWARE is simply returned.

H_INT_ESB is a special case that could have been handled under KVM
but the impact on performance was low when under QEMU. Here are some
figures :

    kernel irqchip      OFF          ON
    H_INT_ESB                    KVM   QEMU

    rtl8139 (LSI )      1.19     1.24  1.23  Gbits/sec
    virtio             31.80    42.30   --   Gbits/sec

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190513084245.25755-4-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Cédric Le Goater 2019-05-13 10:42:34 +02:00 committed by David Gibson
parent 38afd772f8
commit 0c575703e4
3 changed files with 294 additions and 8 deletions

View File

@ -86,6 +86,22 @@ static int spapr_xive_target_to_nvt(uint32_t target,
* sPAPR END indexing uses a simple mapping of the CPU vcpu_id, 8
* priorities per CPU
*/
int spapr_xive_end_to_target(uint8_t end_blk, uint32_t end_idx,
uint32_t *out_server, uint8_t *out_prio)
{
assert(end_blk == SPAPR_XIVE_BLOCK_ID);
if (out_server) {
*out_server = end_idx >> 3;
}
if (out_prio) {
*out_prio = end_idx & 0x7;
}
return 0;
}
static void spapr_xive_cpu_to_end(PowerPCCPU *cpu, uint8_t prio,
uint8_t *out_end_blk, uint32_t *out_end_idx)
{
@ -792,6 +808,16 @@ static target_ulong h_int_set_source_config(PowerPCCPU *cpu,
new_eas.w = xive_set_field64(EAS_END_DATA, new_eas.w, eisn);
}
if (kvm_irqchip_in_kernel()) {
Error *local_err = NULL;
kvmppc_xive_set_source_config(xive, lisn, &new_eas, &local_err);
if (local_err) {
error_report_err(local_err);
return H_HARDWARE;
}
}
out:
xive->eat[lisn] = new_eas;
return H_SUCCESS;
@ -1103,6 +1129,16 @@ static target_ulong h_int_set_queue_config(PowerPCCPU *cpu,
*/
out:
if (kvm_irqchip_in_kernel()) {
Error *local_err = NULL;
kvmppc_xive_set_queue_config(xive, end_blk, end_idx, &end, &local_err);
if (local_err) {
error_report_err(local_err);
return H_HARDWARE;
}
}
/* Update END */
memcpy(&xive->endt[end_idx], &end, sizeof(XiveEND));
return H_SUCCESS;
@ -1194,6 +1230,16 @@ static target_ulong h_int_get_queue_config(PowerPCCPU *cpu,
args[2] = 0;
}
if (kvm_irqchip_in_kernel()) {
Error *local_err = NULL;
kvmppc_xive_get_queue_config(xive, end_blk, end_idx, end, &local_err);
if (local_err) {
error_report_err(local_err);
return H_HARDWARE;
}
}
/* TODO: do we need any locking on the END ? */
if (flags & SPAPR_XIVE_END_DEBUG) {
/* Load the event queue generation number into the return flags */
@ -1346,6 +1392,10 @@ static target_ulong h_int_esb(PowerPCCPU *cpu,
return H_P3;
}
if (kvm_irqchip_in_kernel()) {
args[0] = kvmppc_xive_esb_rw(xsrc, lisn, offset, data,
flags & SPAPR_XIVE_ESB_STORE);
} else {
mmio_addr = xive->vc_base + xive_source_esb_mgmt(xsrc, lisn) + offset;
if (dma_memory_rw(&address_space_memory, mmio_addr, &data, 8,
@ -1355,6 +1405,7 @@ static target_ulong h_int_esb(PowerPCCPU *cpu,
return H_HARDWARE;
}
args[0] = (flags & SPAPR_XIVE_ESB_STORE) ? -1 : data;
}
return H_SUCCESS;
}
@ -1411,7 +1462,20 @@ static target_ulong h_int_sync(PowerPCCPU *cpu,
* This is not needed when running the emulation under QEMU
*/
/* This is not real hardware. Nothing to be done */
/*
* This is not real hardware. Nothing to be done unless when
* under KVM
*/
if (kvm_irqchip_in_kernel()) {
Error *local_err = NULL;
kvmppc_xive_sync_source(xive, lisn, &local_err);
if (local_err) {
error_report_err(local_err);
return H_HARDWARE;
}
}
return H_SUCCESS;
}
@ -1446,6 +1510,16 @@ static target_ulong h_int_reset(PowerPCCPU *cpu,
}
device_reset(DEVICE(xive));
if (kvm_irqchip_in_kernel()) {
Error *local_err = NULL;
kvmppc_xive_reset(xive, &local_err);
if (local_err) {
error_report_err(local_err);
return H_HARDWARE;
}
}
return H_SUCCESS;
}

View File

@ -89,6 +89,50 @@ void kvmppc_xive_cpu_connect(XiveTCTX *tctx, Error **errp)
* XIVE Interrupt Source (KVM)
*/
void 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;
Error *local_err = NULL;
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;
kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_SOURCE_CONFIG, lisn,
&kvm_src, true, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
}
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
@ -125,6 +169,64 @@ void kvmppc_xive_source_reset(XiveSource *xsrc, Error **errp)
}
}
/*
* 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);
}
/*
* 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);
}
}
void kvmppc_xive_source_set_irq(void *opaque, int srcno, int val)
{
XiveSource *xsrc = opaque;
@ -155,6 +257,101 @@ void kvmppc_xive_source_set_irq(void *opaque, int srcno, int val)
/*
* sPAPR XIVE interrupt controller (KVM)
*/
void 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;
Error *local_err = NULL;
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;
kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_EQ_CONFIG, kvm_eq_idx,
&kvm_eq, false, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
/*
* 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);
}
void 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;
Error *local_err = NULL;
/*
* 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;
kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_EQ_CONFIG, kvm_eq_idx,
&kvm_eq, true, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
}
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 void *kvmppc_xive_mmap(SpaprXive *xive, int pgoff, size_t len,
Error **errp)

View File

@ -55,9 +55,24 @@ void spapr_xive_set_tctx_os_cam(XiveTCTX *tctx);
void spapr_xive_mmio_set_enabled(SpaprXive *xive, bool enable);
void spapr_xive_map_mmio(SpaprXive *xive);
int spapr_xive_end_to_target(uint8_t end_blk, uint32_t end_idx,
uint32_t *out_server, uint8_t *out_prio);
/*
* KVM XIVE device helpers
*/
void kvmppc_xive_connect(SpaprXive *xive, Error **errp);
void kvmppc_xive_reset(SpaprXive *xive, Error **errp);
void kvmppc_xive_set_source_config(SpaprXive *xive, uint32_t lisn, XiveEAS *eas,
Error **errp);
void kvmppc_xive_sync_source(SpaprXive *xive, uint32_t lisn, Error **errp);
uint64_t kvmppc_xive_esb_rw(XiveSource *xsrc, int srcno, uint32_t offset,
uint64_t data, bool write);
void kvmppc_xive_set_queue_config(SpaprXive *xive, uint8_t end_blk,
uint32_t end_idx, XiveEND *end,
Error **errp);
void kvmppc_xive_get_queue_config(SpaprXive *xive, uint8_t end_blk,
uint32_t end_idx, XiveEND *end,
Error **errp);
#endif /* PPC_SPAPR_XIVE_H */