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Re: [PATCH v2 2/2] ppc/xive: Add support for PQ state bits offload
From: |
Greg Kurz |
Subject: |
Re: [PATCH v2 2/2] ppc/xive: Add support for PQ state bits offload |
Date: |
Thu, 2 Apr 2020 12:51:55 +0200 |
On Wed, 1 Apr 2020 18:46:53 +0200
Cédric Le Goater <address@hidden> wrote:
> The trigger message coming from a HW source contains a special bit
> informing the XIVE interrupt controller that the PQ bits have been
> checked at the source or not. Depending on the value, the IC can
> perform the check and the state transition locally using its own PQ
> state bits.
>
> The following changes add new accessors to the XiveRouter required to
> query and update the PQ state bits. This is only applies to the
> PowerNV machine, sPAPR is not concerned by such complex configuration.
>
> Signed-off-by: Cédric Le Goater <address@hidden>
> ---
> include/hw/ppc/xive.h | 8 +++++--
> hw/intc/pnv_xive.c | 37 +++++++++++++++++++++++++++++---
> hw/intc/xive.c | 48 ++++++++++++++++++++++++++++++++++++------
> hw/pci-host/pnv_phb4.c | 9 ++++++--
> hw/ppc/pnv_psi.c | 8 +++++--
> 5 files changed, 94 insertions(+), 16 deletions(-)
>
> diff --git a/include/hw/ppc/xive.h b/include/hw/ppc/xive.h
> index 112fb6fb6dbe..050e49c14fd9 100644
> --- a/include/hw/ppc/xive.h
> +++ b/include/hw/ppc/xive.h
> @@ -160,7 +160,7 @@ typedef struct XiveNotifier XiveNotifier;
>
> typedef struct XiveNotifierClass {
> InterfaceClass parent;
> - void (*notify)(XiveNotifier *xn, uint32_t lisn);
> + void (*notify)(XiveNotifier *xn, uint32_t lisn, bool pq_checked);
> } XiveNotifierClass;
>
> /*
> @@ -354,6 +354,10 @@ typedef struct XiveRouterClass {
> /* XIVE table accessors */
> int (*get_eas)(XiveRouter *xrtr, uint8_t eas_blk, uint32_t eas_idx,
> XiveEAS *eas);
> + int (*get_pq)(XiveRouter *xrtr, uint8_t eas_blk, uint32_t eas_idx,
> + uint8_t *pq);
> + int (*set_pq)(XiveRouter *xrtr, uint8_t eas_blk, uint32_t eas_idx,
> + uint8_t *pq);
> int (*get_end)(XiveRouter *xrtr, uint8_t end_blk, uint32_t end_idx,
> XiveEND *end);
> int (*write_end)(XiveRouter *xrtr, uint8_t end_blk, uint32_t end_idx,
> @@ -375,7 +379,7 @@ int xive_router_get_nvt(XiveRouter *xrtr, uint8_t
> nvt_blk, uint32_t nvt_idx,
> XiveNVT *nvt);
> int xive_router_write_nvt(XiveRouter *xrtr, uint8_t nvt_blk, uint32_t
> nvt_idx,
> XiveNVT *nvt, uint8_t word_number);
> -void xive_router_notify(XiveNotifier *xn, uint32_t lisn);
> +void xive_router_notify(XiveNotifier *xn, uint32_t lisn, bool pq_checked);
>
> /*
> * XIVE Presenter
> diff --git a/hw/intc/pnv_xive.c b/hw/intc/pnv_xive.c
> index 77cacdd6c623..bcfe9dc54e3b 100644
> --- a/hw/intc/pnv_xive.c
> +++ b/hw/intc/pnv_xive.c
> @@ -373,6 +373,34 @@ static int pnv_xive_get_eas(XiveRouter *xrtr, uint8_t
> blk, uint32_t idx,
> return pnv_xive_vst_read(xive, VST_TSEL_IVT, blk, idx, eas);
> }
>
> +static int pnv_xive_get_pq(XiveRouter *xrtr, uint8_t blk, uint32_t idx,
> + uint8_t *pq)
> +{
> + PnvXive *xive = PNV_XIVE(xrtr);
> +
> + if (pnv_xive_block_id(xive) != blk) {
> + xive_error(xive, "VST: EAS %x is remote !?", XIVE_EAS(blk, idx));
> + return -1;
> + }
> +
> + *pq = xive_source_esb_get(&xive->ipi_source, idx);
> + return 0;
> +}
> +
> +static int pnv_xive_set_pq(XiveRouter *xrtr, uint8_t blk, uint32_t idx,
> + uint8_t *pq)
> +{
> + PnvXive *xive = PNV_XIVE(xrtr);
> +
> + if (pnv_xive_block_id(xive) != blk) {
> + xive_error(xive, "VST: EAS %x is remote !?", XIVE_EAS(blk, idx));
> + return -1;
> + }
> +
> + *pq = xive_source_esb_set(&xive->ipi_source, idx, *pq);
> + return 0;
> +}
> +
> /*
> * One bit per thread id. The first register PC_THREAD_EN_REG0 covers
> * the first cores 0-15 (normal) of the chip or 0-7 (fused). The
> @@ -469,12 +497,12 @@ static PnvXive *pnv_xive_tm_get_xive(PowerPCCPU *cpu)
> * event notification to the Router. This is required on a multichip
> * system.
> */
> -static void pnv_xive_notify(XiveNotifier *xn, uint32_t srcno)
> +static void pnv_xive_notify(XiveNotifier *xn, uint32_t srcno, bool
> pq_checked)
> {
> PnvXive *xive = PNV_XIVE(xn);
> uint8_t blk = pnv_xive_block_id(xive);
>
> - xive_router_notify(xn, XIVE_EAS(blk, srcno));
> + xive_router_notify(xn, XIVE_EAS(blk, srcno), pq_checked);
> }
>
> /*
> @@ -1316,7 +1344,8 @@ static void pnv_xive_ic_hw_trigger(PnvXive *xive,
> hwaddr addr, uint64_t val)
> blk = XIVE_EAS_BLOCK(val);
> idx = XIVE_EAS_INDEX(val);
>
> - xive_router_notify(XIVE_NOTIFIER(xive), XIVE_EAS(blk, idx));
> + xive_router_notify(XIVE_NOTIFIER(xive), XIVE_EAS(blk, idx),
> + !!(val & XIVE_TRIGGER_PQ));
> }
>
> static void pnv_xive_ic_notify_write(void *opaque, hwaddr addr, uint64_t val,
> @@ -1944,6 +1973,8 @@ static void pnv_xive_class_init(ObjectClass *klass,
> void *data)
> device_class_set_props(dc, pnv_xive_properties);
>
> xrc->get_eas = pnv_xive_get_eas;
> + xrc->get_pq = pnv_xive_get_pq;
> + xrc->set_pq = pnv_xive_set_pq;
> xrc->get_end = pnv_xive_get_end;
> xrc->write_end = pnv_xive_write_end;
> xrc->get_nvt = pnv_xive_get_nvt;
> diff --git a/hw/intc/xive.c b/hw/intc/xive.c
> index b8825577f719..894be4b49ba4 100644
> --- a/hw/intc/xive.c
> +++ b/hw/intc/xive.c
> @@ -927,7 +927,7 @@ static void xive_source_notify(XiveSource *xsrc, int
> srcno)
> XiveNotifierClass *xnc = XIVE_NOTIFIER_GET_CLASS(xsrc->xive);
>
> if (xnc->notify) {
> - xnc->notify(xsrc->xive, srcno);
> + xnc->notify(xsrc->xive, srcno, true);
> }
> }
>
> @@ -1343,6 +1343,24 @@ int xive_router_get_eas(XiveRouter *xrtr, uint8_t
> eas_blk, uint32_t eas_idx,
> return xrc->get_eas(xrtr, eas_blk, eas_idx, eas);
> }
>
> +static
> +int xive_router_get_pq(XiveRouter *xrtr, uint8_t eas_blk, uint32_t eas_idx,
> + uint8_t *pq)
> +{
> + XiveRouterClass *xrc = XIVE_ROUTER_GET_CLASS(xrtr);
> +
> + return xrc->get_pq(xrtr, eas_blk, eas_idx, pq);
> +}
> +
> +static
> +int xive_router_set_pq(XiveRouter *xrtr, uint8_t eas_blk, uint32_t eas_idx,
> + uint8_t *pq)
> +{
> + XiveRouterClass *xrc = XIVE_ROUTER_GET_CLASS(xrtr);
> +
> + return xrc->set_pq(xrtr, eas_blk, eas_idx, pq);
> +}
> +
Only the powernv machine implements the PQ bits hooks. I understand
that pseries doesn't need them because it cannot execute the helpers
above in practice, since xive_router_notify() is always called with
pq_checked == true :
spapr_xive_set_irq()
xive_source_set_irq()
xive_source_notify()
{
xnc->notify(xsrc->xive, srcno, true);
}
IMHO the XIVE code is complex enough that we should maybe make
this really explicit with a comment and assert(xrc->[sg]et_pq)
in the PQ bits helpers.
> int xive_router_get_end(XiveRouter *xrtr, uint8_t end_blk, uint32_t end_idx,
> XiveEND *end)
> {
> @@ -1686,7 +1704,7 @@ do_escalation:
> xive_get_field32(END_W5_ESC_END_DATA, end.w5));
> }
>
> -void xive_router_notify(XiveNotifier *xn, uint32_t lisn)
> +void xive_router_notify(XiveNotifier *xn, uint32_t lisn, bool pq_checked)
> {
> XiveRouter *xrtr = XIVE_ROUTER(xn);
> uint8_t eas_blk = XIVE_EAS_BLOCK(lisn);
> @@ -1699,11 +1717,27 @@ void xive_router_notify(XiveNotifier *xn, uint32_t
> lisn)
> return;
> }
>
> - /*
> - * The IVRE checks the State Bit Cache at this point. We skip the
> - * SBC lookup because the state bits of the sources are modeled
> - * internally in QEMU.
> - */
> + if (!pq_checked) {
> + bool notify;
> + uint8_t pq;
> +
> + /* PQ cache lookup */
> + if (xive_router_get_pq(xrtr, eas_blk, eas_idx, &pq)) {
> + /* Set FIR */
> + g_assert_not_reached();
I'm not sure about the intent of this assert... Actual QEMU
bug that should never happen ever or guest misuse of XIVE
that we might try to handle one day ?
In the former case, I'd rather assert() in the PQ bits
machine hooks when the error condition is first detected.
Apart from that, rest looks good.
> + }
> +
> + notify = xive_esb_trigger(&pq);
> +
> + if (xive_router_set_pq(xrtr, eas_blk, eas_idx, &pq)) {
> + /* Set FIR */
> + g_assert_not_reached();
> + }
> +
> + if (!notify) {
> + return;
> + }
> + }
>
> if (!xive_eas_is_valid(&eas)) {
> qemu_log_mask(LOG_GUEST_ERROR, "XIVE: invalid LISN %x\n", lisn);
> diff --git a/hw/pci-host/pnv_phb4.c b/hw/pci-host/pnv_phb4.c
> index ac824f877cf1..c451819bfd52 100644
> --- a/hw/pci-host/pnv_phb4.c
> +++ b/hw/pci-host/pnv_phb4.c
> @@ -1241,14 +1241,19 @@ static const char
> *pnv_phb4_root_bus_path(PCIHostState *host_bridge,
> return phb->bus_path;
> }
>
> -static void pnv_phb4_xive_notify(XiveNotifier *xf, uint32_t srcno)
> +static void pnv_phb4_xive_notify(XiveNotifier *xf, uint32_t srcno,
> + bool pq_checked)
> {
> PnvPHB4 *phb = PNV_PHB4(xf);
> uint64_t notif_port = phb->regs[PHB_INT_NOTIFY_ADDR >> 3];
> uint32_t offset = phb->regs[PHB_INT_NOTIFY_INDEX >> 3];
> - uint64_t data = XIVE_TRIGGER_PQ | offset | srcno;
> + uint64_t data = offset | srcno;
> MemTxResult result;
>
> + if (pq_checked) {
> + data |= XIVE_TRIGGER_PQ;
> + }
> +
> address_space_stq_be(&address_space_memory, notif_port, data,
> MEMTXATTRS_UNSPECIFIED, &result);
> if (result != MEMTX_OK) {
> diff --git a/hw/ppc/pnv_psi.c b/hw/ppc/pnv_psi.c
> index c34a49b000f2..63804f28f45e 100644
> --- a/hw/ppc/pnv_psi.c
> +++ b/hw/ppc/pnv_psi.c
> @@ -652,7 +652,7 @@ static const TypeInfo pnv_psi_power8_info = {
> #define PSIHB9_IRQ_STAT_DIO PPC_BIT(12)
> #define PSIHB9_IRQ_STAT_PSU PPC_BIT(13)
>
> -static void pnv_psi_notify(XiveNotifier *xf, uint32_t srcno)
> +static void pnv_psi_notify(XiveNotifier *xf, uint32_t srcno, bool pq_checked)
> {
> PnvPsi *psi = PNV_PSI(xf);
> uint64_t notif_port = psi->regs[PSIHB_REG(PSIHB9_ESB_NOTIF_ADDR)];
> @@ -661,9 +661,13 @@ static void pnv_psi_notify(XiveNotifier *xf, uint32_t
> srcno)
>
> uint32_t offset =
> (psi->regs[PSIHB_REG(PSIHB9_IVT_OFFSET)] >> PSIHB9_IVT_OFF_SHIFT);
> - uint64_t data = XIVE_TRIGGER_PQ | offset | srcno;
> + uint64_t data = offset | srcno;
> MemTxResult result;
>
> + if (pq_checked) {
> + data |= XIVE_TRIGGER_PQ;
> + }
> +
> if (!valid) {
> return;
> }