From 36ab3c3400ac941e4d9afc044be08143ff9eea62 Mon Sep 17 00:00:00 2001 From: John Snow Date: Mon, 3 Nov 2014 18:56:17 -0500 Subject: [PATCH] ahci: Reorder error cases in handle_cmd Error checking in ahci's handle_cmd is re-ordered so that we initialize as few things as possible before we've done our sanity checking. This simplifies returning from this call in case of an error. A check to make sure the DMA memory map succeeds with the correct size is also added, and the debug print of the command fis is cleaned up with its size corrected. Signed-off-by: John Snow Reviewed-by: Paolo Bonzini Message-id: 1415058979-16604-4-git-send-email-jsnow@redhat.com Signed-off-by: Stefan Hajnoczi --- hw/ide/ahci.c | 39 +++++++++++++++++++-------------------- 1 file changed, 19 insertions(+), 20 deletions(-) diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c index 43da3637da..578a93b627 100644 --- a/hw/ide/ahci.c +++ b/hw/ide/ahci.c @@ -961,38 +961,37 @@ static int handle_cmd(AHCIState *s, int port, int slot) return -1; } - cmd = &((AHCICmdHdr *)s->dev[port].lst)[slot]; - if (!s->dev[port].lst) { DPRINTF(port, "error: lst not given but cmd handled"); return -1; } - + cmd = &((AHCICmdHdr *)s->dev[port].lst)[slot]; /* remember current slot handle for later */ s->dev[port].cur_cmd = cmd; - opts = le32_to_cpu(cmd->opts); - tbl_addr = le64_to_cpu(cmd->tbl_addr); - - cmd_len = 0x80; - cmd_fis = dma_memory_map(s->as, tbl_addr, &cmd_len, - DMA_DIRECTION_FROM_DEVICE); - - if (!cmd_fis) { - DPRINTF(port, "error: guest passed us an invalid cmd fis\n"); + /* The device we are working for */ + ide_state = &s->dev[port].port.ifs[0]; + if (!ide_state->blk) { + DPRINTF(port, "error: guest accessed unused port"); return -1; } - /* The device we are working for */ - ide_state = &s->dev[port].port.ifs[0]; - - if (!ide_state->blk) { - DPRINTF(port, "error: guest accessed unused port"); + opts = le32_to_cpu(cmd->opts); + tbl_addr = le64_to_cpu(cmd->tbl_addr); + cmd_len = 0x80; + cmd_fis = dma_memory_map(s->as, tbl_addr, &cmd_len, + DMA_DIRECTION_FROM_DEVICE); + if (!cmd_fis) { + DPRINTF(port, "error: guest passed us an invalid cmd fis\n"); + return -1; + } else if (cmd_len != 0x80) { + ahci_trigger_irq(s, &s->dev[port], PORT_IRQ_HBUS_ERR); + DPRINTF(port, "error: dma_memory_map failed: " + "(len(%02"PRIx64") != 0x80)\n", + cmd_len); goto out; } - - debug_print_fis(cmd_fis, 0x90); - //debug_print_fis(cmd_fis, (opts & AHCI_CMD_HDR_CMD_FIS_LEN) * 4); + debug_print_fis(cmd_fis, 0x80); switch (cmd_fis[0]) { case SATA_FIS_TYPE_REGISTER_H2D: