From 26c55b99418173107897b28ffdb8171e913339e9 Mon Sep 17 00:00:00 2001 From: Frederic Barrat Date: Tue, 11 Mar 2025 11:51:22 +1000 Subject: [PATCH] ppc/xive2: Process group backlog when updating the CPPR When the hypervisor or OS pushes a new value to the CPPR, if the LSMFB value is lower than the new CPPR value, there could be a pending group interrupt in the backlog, so it needs to be scanned. Signed-off-by: Frederic Barrat Signed-off-by: Michael Kowal Reviewed-by: Nicholas Piggin Signed-off-by: Nicholas Piggin --- hw/intc/xive.c | 4 +- hw/intc/xive2.c | 173 ++++++++++++++++++++++++++++++++++++++++- include/hw/ppc/xive2.h | 4 + 3 files changed, 177 insertions(+), 4 deletions(-) diff --git a/hw/intc/xive.c b/hw/intc/xive.c index 3e4c932f19..535e59646f 100644 --- a/hw/intc/xive.c +++ b/hw/intc/xive.c @@ -589,7 +589,7 @@ static const XiveTmOp xive2_tm_operations[] = { * MMIOs below 2K : raw values and special operations without side * effects */ - { XIVE_TM_OS_PAGE, TM_QW1_OS + TM_CPPR, 1, xive_tm_set_os_cppr, + { XIVE_TM_OS_PAGE, TM_QW1_OS + TM_CPPR, 1, xive2_tm_set_os_cppr, NULL }, { XIVE_TM_HV_PAGE, TM_QW1_OS + TM_WORD2, 4, xive2_tm_push_os_ctx, NULL }, @@ -597,7 +597,7 @@ static const XiveTmOp xive2_tm_operations[] = { NULL }, { XIVE_TM_OS_PAGE, TM_QW1_OS + TM_LGS, 1, xive_tm_set_os_lgs, NULL }, - { XIVE_TM_HV_PAGE, TM_QW3_HV_PHYS + TM_CPPR, 1, xive_tm_set_hv_cppr, + { XIVE_TM_HV_PAGE, TM_QW3_HV_PHYS + TM_CPPR, 1, xive2_tm_set_hv_cppr, NULL }, { XIVE_TM_HV_PAGE, TM_QW3_HV_PHYS + TM_WORD2, 1, xive_tm_vt_push, NULL }, diff --git a/hw/intc/xive2.c b/hw/intc/xive2.c index 2fa7b90669..017c0f8bb4 100644 --- a/hw/intc/xive2.c +++ b/hw/intc/xive2.c @@ -17,6 +17,7 @@ #include "hw/ppc/xive.h" #include "hw/ppc/xive2.h" #include "hw/ppc/xive2_regs.h" +#include "trace.h" uint32_t xive2_router_get_config(Xive2Router *xrtr) { @@ -768,6 +769,172 @@ void xive2_tm_push_os_ctx(XivePresenter *xptr, XiveTCTX *tctx, } } +static int xive2_tctx_get_nvp_indexes(XiveTCTX *tctx, uint8_t ring, + uint32_t *nvp_blk, uint32_t *nvp_idx) +{ + uint32_t w2, cam; + + w2 = xive_tctx_word2(&tctx->regs[ring]); + switch (ring) { + case TM_QW1_OS: + if (!(be32_to_cpu(w2) & TM2_QW1W2_VO)) { + return -1; + } + cam = xive_get_field32(TM2_QW1W2_OS_CAM, w2); + break; + case TM_QW2_HV_POOL: + if (!(be32_to_cpu(w2) & TM2_QW2W2_VP)) { + return -1; + } + cam = xive_get_field32(TM2_QW2W2_POOL_CAM, w2); + break; + case TM_QW3_HV_PHYS: + if (!(be32_to_cpu(w2) & TM2_QW3W2_VT)) { + return -1; + } + cam = xive2_tctx_hw_cam_line(tctx->xptr, tctx); + break; + default: + return -1; + } + *nvp_blk = xive2_nvp_blk(cam); + *nvp_idx = xive2_nvp_idx(cam); + return 0; +} + +static void xive2_tctx_set_cppr(XiveTCTX *tctx, uint8_t ring, uint8_t cppr) +{ + uint8_t *regs = &tctx->regs[ring]; + Xive2Router *xrtr = XIVE2_ROUTER(tctx->xptr); + uint8_t old_cppr, backlog_prio, first_group, group_level = 0; + uint8_t pipr_min, lsmfb_min, ring_min; + bool group_enabled; + uint32_t nvp_blk, nvp_idx; + Xive2Nvp nvp; + int rc; + + trace_xive_tctx_set_cppr(tctx->cs->cpu_index, ring, + regs[TM_IPB], regs[TM_PIPR], + cppr, regs[TM_NSR]); + + if (cppr > XIVE_PRIORITY_MAX) { + cppr = 0xff; + } + + old_cppr = regs[TM_CPPR]; + regs[TM_CPPR] = cppr; + + /* + * Recompute the PIPR based on local pending interrupts. It will + * be adjusted below if needed in case of pending group interrupts. + */ + pipr_min = xive_ipb_to_pipr(regs[TM_IPB]); + group_enabled = !!regs[TM_LGS]; + lsmfb_min = (group_enabled) ? regs[TM_LSMFB] : 0xff; + ring_min = ring; + + /* PHYS updates also depend on POOL values */ + if (ring == TM_QW3_HV_PHYS) { + uint8_t *pregs = &tctx->regs[TM_QW2_HV_POOL]; + + /* POOL values only matter if POOL ctx is valid */ + if (pregs[TM_WORD2] & 0x80) { + + uint8_t pool_pipr = xive_ipb_to_pipr(pregs[TM_IPB]); + uint8_t pool_lsmfb = pregs[TM_LSMFB]; + + /* + * Determine highest priority interrupt and + * remember which ring has it. + */ + if (pool_pipr < pipr_min) { + pipr_min = pool_pipr; + if (pool_pipr < lsmfb_min) { + ring_min = TM_QW2_HV_POOL; + } + } + + /* Values needed for group priority calculation */ + if (pregs[TM_LGS] && (pool_lsmfb < lsmfb_min)) { + group_enabled = true; + lsmfb_min = pool_lsmfb; + if (lsmfb_min < pipr_min) { + ring_min = TM_QW2_HV_POOL; + } + } + } + } + regs[TM_PIPR] = pipr_min; + + rc = xive2_tctx_get_nvp_indexes(tctx, ring_min, &nvp_blk, &nvp_idx); + if (rc) { + qemu_log_mask(LOG_GUEST_ERROR, "XIVE: set CPPR on invalid context\n"); + return; + } + + if (cppr < old_cppr) { + /* + * FIXME: check if there's a group interrupt being presented + * and if the new cppr prevents it. If so, then the group + * interrupt needs to be re-added to the backlog and + * re-triggered (see re-trigger END info in the NVGC + * structure) + */ + } + + if (group_enabled && + lsmfb_min < cppr && + lsmfb_min < regs[TM_PIPR]) { + /* + * Thread has seen a group interrupt with a higher priority + * than the new cppr or pending local interrupt. Check the + * backlog + */ + if (xive2_router_get_nvp(xrtr, nvp_blk, nvp_idx, &nvp)) { + qemu_log_mask(LOG_GUEST_ERROR, "XIVE: No NVP %x/%x\n", + nvp_blk, nvp_idx); + return; + } + + if (!xive2_nvp_is_valid(&nvp)) { + qemu_log_mask(LOG_GUEST_ERROR, "XIVE: invalid NVP %x/%x\n", + nvp_blk, nvp_idx); + return; + } + + first_group = xive_get_field32(NVP2_W0_PGOFIRST, nvp.w0); + if (!first_group) { + qemu_log_mask(LOG_GUEST_ERROR, "XIVE: invalid NVP %x/%x\n", + nvp_blk, nvp_idx); + return; + } + + backlog_prio = xive2_presenter_backlog_scan(tctx->xptr, + nvp_blk, nvp_idx, + first_group, &group_level); + tctx->regs[ring_min + TM_LSMFB] = backlog_prio; + if (backlog_prio != 0xFF) { + xive2_presenter_backlog_decr(tctx->xptr, nvp_blk, nvp_idx, + backlog_prio, group_level); + regs[TM_PIPR] = backlog_prio; + } + } + /* CPPR has changed, check if we need to raise a pending exception */ + xive_tctx_notify(tctx, ring_min, group_level); +} + +void xive2_tm_set_hv_cppr(XivePresenter *xptr, XiveTCTX *tctx, + hwaddr offset, uint64_t value, unsigned size) +{ + xive2_tctx_set_cppr(tctx, TM_QW3_HV_PHYS, value & 0xff); +} + +void xive2_tm_set_os_cppr(XivePresenter *xptr, XiveTCTX *tctx, + hwaddr offset, uint64_t value, unsigned size) +{ + xive2_tctx_set_cppr(tctx, TM_QW1_OS, value & 0xff); +} + static void xive2_tctx_set_target(XiveTCTX *tctx, uint8_t ring, uint8_t target) { uint8_t *regs = &tctx->regs[ring]; @@ -938,7 +1105,9 @@ int xive2_presenter_tctx_match(XivePresenter *xptr, XiveTCTX *tctx, bool xive2_tm_irq_precluded(XiveTCTX *tctx, int ring, uint8_t priority) { - uint8_t *regs = &tctx->regs[ring]; + /* HV_POOL ring uses HV_PHYS NSR, CPPR and PIPR registers */ + uint8_t alt_ring = (ring == TM_QW2_HV_POOL) ? TM_QW3_HV_PHYS : ring; + uint8_t *alt_regs = &tctx->regs[alt_ring]; /* * The xive2_presenter_tctx_match() above tells if there's a match @@ -946,7 +1115,7 @@ bool xive2_tm_irq_precluded(XiveTCTX *tctx, int ring, uint8_t priority) * priority to know if the thread can take the interrupt now or if * it is precluded. */ - if (priority < regs[TM_CPPR]) { + if (priority < alt_regs[TM_CPPR]) { return false; } return true; diff --git a/include/hw/ppc/xive2.h b/include/hw/ppc/xive2.h index ebf301bb5b..fc7422fea7 100644 --- a/include/hw/ppc/xive2.h +++ b/include/hw/ppc/xive2.h @@ -113,6 +113,10 @@ typedef struct Xive2EndSource { * XIVE2 Thread Interrupt Management Area (POWER10) */ +void xive2_tm_set_hv_cppr(XivePresenter *xptr, XiveTCTX *tctx, + hwaddr offset, uint64_t value, unsigned size); +void xive2_tm_set_os_cppr(XivePresenter *xptr, XiveTCTX *tctx, + hwaddr offset, uint64_t value, unsigned size); void xive2_tm_push_os_ctx(XivePresenter *xptr, XiveTCTX *tctx, hwaddr offset, uint64_t value, unsigned size); uint64_t xive2_tm_pull_os_ctx(XivePresenter *xptr, XiveTCTX *tctx, -- 2.39.5