From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37236) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XHgXE-00026V-Sl for qemu-devel@nongnu.org; Wed, 13 Aug 2014 17:56:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XHgX8-0000YL-NV for qemu-devel@nongnu.org; Wed, 13 Aug 2014 17:56:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:23705) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XHgX8-0000Y3-GC for qemu-devel@nongnu.org; Wed, 13 Aug 2014 17:56:38 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s7DLubwJ019910 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Wed, 13 Aug 2014 17:56:38 -0400 From: John Snow Date: Wed, 13 Aug 2014 17:56:12 -0400 Message-Id: <1407966975-3723-6-git-send-email-jsnow@redhat.com> In-Reply-To: <1407966975-3723-1-git-send-email-jsnow@redhat.com> References: <1407966975-3723-1-git-send-email-jsnow@redhat.com> Subject: [Qemu-devel] [PATCH v3 29/32] ahci: properly shadow the TFD register List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: jsnow@redhat.com, armbru@redhat.com, stefanha@redhat.com, mst@redhat.com In a real AHCI device, several S/ATA registers are mirrored or shadowed within the AHCI register set. These registers are not updated synchronously for each read access, but rather after a Device-to-Host Register FIS packet is received, which contains the values from these registers on the device. In QEMU, by reaching directly into the device to grab these bits before they are "sent," we may introduce race conditions where unexpected values are present "before they are sent" which could cause issues for some guests, particularly if an attempt is made to read the PxTFD register prior to enabling the port, where incorrect values will be read. This patch also addresses the boot-time values for the PxTFD and PxSIG registers to bring them in line with the AHCI 1.3 specification. Signed-off-by: John Snow --- hw/ide/ahci.c | 42 ++++++++++++++++++++++++++++-------------- 1 file changed, 28 insertions(+), 14 deletions(-) diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c index 4cda0d0..00d8a7a 100644 --- a/hw/ide/ahci.c +++ b/hw/ide/ahci.c @@ -78,8 +78,7 @@ static uint32_t ahci_port_read(AHCIState *s, int port, int offset) val = pr->cmd; break; case PORT_TFDATA: - val = ((uint16_t)s->dev[port].port.ifs[0].error << 8) | - s->dev[port].port.ifs[0].status; + val = pr->tfdata; break; case PORT_SIG: val = pr->sig; @@ -251,14 +250,13 @@ static void ahci_port_write(AHCIState *s, int port, int offset, uint32_t val) check_cmd(s, port); break; case PORT_TFDATA: - s->dev[port].port.ifs[0].error = (val >> 8) & 0xff; - s->dev[port].port.ifs[0].status = val & 0xff; + /* Read Only. */ break; case PORT_SIG: - pr->sig = val; + /* Read Only */ break; case PORT_SCR_STAT: - pr->scr_stat = val; + /* Read Only */ break; case PORT_SCR_CTL: if (((pr->scr_ctl & AHCI_SCR_SCTL_DET) == 1) && @@ -497,6 +495,8 @@ static void ahci_reset_port(AHCIState *s, int port) pr->scr_stat = 0; pr->scr_err = 0; pr->scr_act = 0; + pr->tfdata = 0x7F; + pr->sig = 0xFFFFFFFF; d->busy_slot = -1; d->init_d2h_sent = false; @@ -528,16 +528,16 @@ static void ahci_reset_port(AHCIState *s, int port) s->dev[port].port_state = STATE_RUN; if (!ide_state->bs) { - s->dev[port].port_regs.sig = 0; + pr->sig = 0; ide_state->status = SEEK_STAT | WRERR_STAT; } else if (ide_state->drive_kind == IDE_CD) { - s->dev[port].port_regs.sig = SATA_SIGNATURE_CDROM; + pr->sig = SATA_SIGNATURE_CDROM; ide_state->lcyl = 0x14; ide_state->hcyl = 0xeb; DPRINTF(port, "set lcyl = %d\n", ide_state->lcyl); ide_state->status = SEEK_STAT | WRERR_STAT | READY_STAT; } else { - s->dev[port].port_regs.sig = SATA_SIGNATURE_DISK; + pr->sig = SATA_SIGNATURE_DISK; ide_state->status = SEEK_STAT | WRERR_STAT; } @@ -563,7 +563,8 @@ static void debug_print_fis(uint8_t *fis, int cmd_len) static void ahci_write_fis_sdb(AHCIState *s, int port, uint32_t finished) { - AHCIPortRegs *pr = &s->dev[port].port_regs; + AHCIDevice *ad = &s->dev[port]; + AHCIPortRegs *pr = &ad->port_regs; IDEState *ide_state; uint8_t *sdb_fis; @@ -572,8 +573,8 @@ static void ahci_write_fis_sdb(AHCIState *s, int port, uint32_t finished) return; } - sdb_fis = &s->dev[port].res_fis[RES_FIS_SDBFIS]; - ide_state = &s->dev[port].port.ifs[0]; + sdb_fis = &ad->res_fis[RES_FIS_SDBFIS]; + ide_state = &ad->port.ifs[0]; /* clear memory */ *(uint32_t*)sdb_fis = 0; @@ -582,9 +583,14 @@ static void ahci_write_fis_sdb(AHCIState *s, int port, uint32_t finished) sdb_fis[0] = ide_state->error; sdb_fis[2] = ide_state->status & 0x77; s->dev[port].finished |= finished; - *(uint32_t*)(sdb_fis + 4) = cpu_to_le32(s->dev[port].finished); + *(uint32_t*)(sdb_fis + 4) = cpu_to_le32(ad->finished); - ahci_trigger_irq(s, &s->dev[port], PORT_IRQ_SDB_FIS); + /* Update shadow registers (except BSY 0x80 and DRQ 0x08) */ + pr->tfdata = (ad->port.ifs[0].error << 8) | + (ad->port.ifs[0].status & 0x77) | + (pr->tfdata & 0x88); + + ahci_trigger_irq(s, ad, PORT_IRQ_SDB_FIS); } static void ahci_write_fis_pio(AHCIDevice *ad, uint16_t len) @@ -642,6 +648,10 @@ static void ahci_write_fis_pio(AHCIDevice *ad, uint16_t len) pio_fis[18] = 0; pio_fis[19] = 0; + /* Update shadow registers: */ + pr->tfdata = (ad->port.ifs[0].error << 8) | + ad->port.ifs[0].status; + if (pio_fis[2] & ERR_STAT) { ahci_trigger_irq(ad->hba, ad, PORT_IRQ_TF_ERR); } @@ -693,6 +703,10 @@ static void ahci_write_fis_d2h(AHCIDevice *ad, uint8_t *cmd_fis) d2h_fis[i] = 0; } + /* Update shadow registers: */ + pr->tfdata = (ad->port.ifs[0].error << 8) | + ad->port.ifs[0].status; + if (d2h_fis[2] & ERR_STAT) { ahci_trigger_irq(ad->hba, ad, PORT_IRQ_TF_ERR); } -- 1.9.3