From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:44656) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UVJF1-0005Sk-DJ for qemu-devel@nongnu.org; Thu, 25 Apr 2013 06:17:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UVJEw-00029r-IX for qemu-devel@nongnu.org; Thu, 25 Apr 2013 06:17:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56547) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UVJEw-00029l-Ak for qemu-devel@nongnu.org; Thu, 25 Apr 2013 06:17:22 -0400 From: Hans de Goede Date: Thu, 25 Apr 2013 12:21:07 +0200 Message-Id: <1366885267-9694-1-git-send-email-hdegoede@redhat.com> Subject: [Qemu-devel] [PATCH] uhci: Use an intermediate buffer for usb packet data List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gerd Hoffmann Cc: Jan Kiszka , qemu-devel@nongnu.org, Hans de Goede Due to various unfortunate reasons we cannot reliable detect a guest cancelling a packet as soon as it happens, instead we detect cancels with some delay. When packets are handled async, and we directly pass the guest memory for the packet to the usb-device as iovec, this means that the usb-device can write to guest-memory which the guest has already re-used for other purposes -> not good! This patch fixes this by adding an intermediate buffer and writing back not only the result, but also the data, of async completed packets when scanning the schedule. Signed-off-by: Hans de Goede --- hw/usb/hcd-uhci.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/hw/usb/hcd-uhci.c b/hw/usb/hcd-uhci.c index f8c4286..5f8411b 100644 --- a/hw/usb/hcd-uhci.c +++ b/hw/usb/hcd-uhci.c @@ -119,7 +119,8 @@ struct UHCIPCIDeviceClass { struct UHCIAsync { USBPacket packet; - QEMUSGList sgl; + uint8_t static_buf[64]; /* 64 bytes is enough, except for isoc packets */ + uint8_t *buf; UHCIQueue *queue; QTAILQ_ENTRY(UHCIAsync) next; uint32_t td_addr; @@ -264,7 +265,6 @@ static UHCIAsync *uhci_async_alloc(UHCIQueue *queue, uint32_t td_addr) async->queue = queue; async->td_addr = td_addr; usb_packet_init(&async->packet); - pci_dma_sglist_init(&async->sgl, &queue->uhci->dev, 1); trace_usb_uhci_packet_add(async->queue->token, async->td_addr); return async; @@ -274,7 +274,9 @@ static void uhci_async_free(UHCIAsync *async) { trace_usb_uhci_packet_del(async->queue->token, async->td_addr); usb_packet_cleanup(&async->packet); - qemu_sglist_destroy(&async->sgl); + if (async->buf != async->static_buf) { + g_free(async->buf); + } g_free(async); } @@ -299,7 +301,6 @@ static void uhci_async_cancel(UHCIAsync *async) async->done); if (!async->done) usb_cancel_packet(&async->packet); - usb_packet_unmap(&async->packet, &async->sgl); uhci_async_free(async); } @@ -774,6 +775,7 @@ static int uhci_complete_td(UHCIState *s, UHCI_TD *td, UHCIAsync *async, uint32_ *int_mask |= 0x01; if (pid == USB_TOKEN_IN) { + pci_dma_write(&s->dev, td->buffer, async->buf, len); if ((td->ctrl & TD_CTRL_SPD) && len < max_len) { *int_mask |= 0x02; /* short packet: do not update QH */ @@ -881,12 +883,17 @@ static int uhci_handle_td(UHCIState *s, UHCIQueue *q, uint32_t qh_addr, spd = (pid == USB_TOKEN_IN && (td->ctrl & TD_CTRL_SPD) != 0); usb_packet_setup(&async->packet, pid, q->ep, 0, td_addr, spd, (td->ctrl & TD_CTRL_IOC) != 0); - qemu_sglist_add(&async->sgl, td->buffer, max_len); - usb_packet_map(&async->packet, &async->sgl); + if (max_len <= sizeof(async->static_buf)) { + async->buf = async->static_buf; + } else { + async->buf = g_malloc(max_len); + } + qemu_iovec_add(&async->packet.iov, async->buf, max_len); switch(pid) { case USB_TOKEN_OUT: case USB_TOKEN_SETUP: + pci_dma_read(&s->dev, td->buffer, async->buf, max_len); usb_handle_packet(q->ep->dev, &async->packet); if (async->packet.status == USB_RET_SUCCESS) { async->packet.actual_length = max_len; @@ -899,7 +906,6 @@ static int uhci_handle_td(UHCIState *s, UHCIQueue *q, uint32_t qh_addr, default: /* invalid pid : frame interrupted */ - usb_packet_unmap(&async->packet, &async->sgl); uhci_async_free(async); s->status |= UHCI_STS_HCPERR; uhci_update_irq(s); @@ -916,7 +922,6 @@ static int uhci_handle_td(UHCIState *s, UHCIQueue *q, uint32_t qh_addr, done: ret = uhci_complete_td(s, td, async, int_mask); - usb_packet_unmap(&async->packet, &async->sgl); uhci_async_free(async); return ret; } -- 1.8.2.1