From 4e98327e1480399beeb57fab618f2495b8ba2d2c Mon Sep 17 00:00:00 2001 From: Klaus Jensen Date: Thu, 8 Dec 2022 09:12:45 +0100 Subject: [PATCH] hw/nvme: fix missing cq eventidx update Prior to reading the shadow doorbell cq head, we have to update the eventidx. Otherwise, we risk that the driver will skip an mmio doorbell write. This happens on riscv64, as reported by Guenter. Adding the missing update to the cq eventidx fixes the issue. Fixes: 3f7fe8de3d49 ("hw/nvme: Implement shadow doorbell buffer support") Cc: qemu-stable@nongnu.org Cc: qemu-riscv@nongnu.org Reported-by: Guenter Roeck Reviewed-by: Keith Busch Signed-off-by: Klaus Jensen (cherry picked from commit fa5db2aa168bdc0f15c269b6212ef47632fab8ba) Signed-off-by: Michael Tokarev --- hw/nvme/ctrl.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c index 98d8e34109..1d3e058452 100644 --- a/hw/nvme/ctrl.c +++ b/hw/nvme/ctrl.c @@ -1331,6 +1331,15 @@ static inline void nvme_blk_write(BlockBackend *blk, int64_t offset, } } +static void nvme_update_cq_eventidx(const NvmeCQueue *cq) +{ + uint32_t v = cpu_to_le32(cq->head); + + //not in 7.2: trace_pci_nvme_update_cq_eventidx(cq->cqid, cq->head); + + pci_dma_write(PCI_DEVICE(cq->ctrl), cq->ei_addr, &v, sizeof(v)); +} + static void nvme_update_cq_head(NvmeCQueue *cq) { uint32_t v; @@ -1355,6 +1364,7 @@ static void nvme_post_cqes(void *opaque) hwaddr addr; if (n->dbbuf_enabled) { + nvme_update_cq_eventidx(cq); nvme_update_cq_head(cq); }