From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58705) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fWKAO-0007XP-QV for qemu-devel@nongnu.org; Fri, 22 Jun 2018 07:23:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fWKAN-0005aa-PA for qemu-devel@nongnu.org; Fri, 22 Jun 2018 07:23:48 -0400 From: Shimi Gersner Date: Fri, 22 Jun 2018 11:22:37 +0000 Message-Id: <20180622112237.2131-5-gersner@gmail.com> In-Reply-To: <20180622112237.2131-1-gersner@gmail.com> References: <20180622112237.2131-1-gersner@gmail.com> Subject: [Qemu-devel] [PATCH 5/5] nvme: Missing MSI message upon partial CQ read List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org, qemu-devel@nongnu.org Cc: Keith Busch , Kevin Wolf , Max Reitz , David Sariel , Shimi Gersner When MSIx interrupts are enabled, each CQ is associated with a vector which is expected to be called upon ready data in the CQ buffer. After guest reads from the buffer, it updates the processed buffer position using a CQ dedicated DB. Upon reading only partial data from the CQ buffer, device fails to re-send a new MSI message stating buffer still has unread data. The fix ensures a new message will be sent. Change-Id: I10190be127b8dcbd89732cfb95ea37faf8c5779b Signed-off-by: Shimi Gersner --- hw/block/nvme.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/hw/block/nvme.c b/hw/block/nvme.c index f639d7ae73..e2dca6e57f 100644 --- a/hw/block/nvme.c +++ b/hw/block/nvme.c @@ -1152,8 +1152,12 @@ static void nvme_process_db(NvmeCtrl *n, hwaddr addr, int val) } } + // When we have more messages, we should make sure irq is asserted. When MSIx is used + // this will make sure another notification is sent to the guest. if (cq->tail == cq->head) { nvme_irq_deassert(n, cq); + } else { + nvme_irq_assert(n, cq); } } else { /* Submission queue doorbell write */ -- 2.17.1