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[Qemu-devel] [PULL 11/11] ahci: prohibit "restarting" the FIS or CLB eng
From: |
John Snow |
Subject: |
[Qemu-devel] [PULL 11/11] ahci: prohibit "restarting" the FIS or CLB engines |
Date: |
Wed, 10 Feb 2016 14:38:09 -0500 |
If the FIS or DMA engines are already started, do not allow them to be
"restarted." As a side-effect of this change, the migration post-load
routine must be modified to cope. If the engines are listed as "on"
in the migrated registers, they must be cleared to allow the startup
routine to see the transition from "off" to "on".
As a second side-effect, the extra argument to ahci_cond_engine_start
is removed in favor of consistent behavior.
Signed-off-by: John Snow <address@hidden>
Message-id: address@hidden
---
hw/ide/ahci.c | 39 ++++++++++++++++++++-------------------
1 file changed, 20 insertions(+), 19 deletions(-)
diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index 9f4a672..f244bc0 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -199,38 +199,38 @@ static void map_page(AddressSpace *as, uint8_t **ptr,
uint64_t addr,
* Check the cmd register to see if we should start or stop
* the DMA or FIS RX engines.
*
- * @ad: Device to engage.
- * @allow_stop: Allow device to transition from started to stopped?
- * 'no' is useful for migration post_load, which does not expect a
transition.
+ * @ad: Device to dis/engage.
*
* @return 0 on success, -1 on error.
*/
-static int ahci_cond_start_engines(AHCIDevice *ad, bool allow_stop)
+static int ahci_cond_start_engines(AHCIDevice *ad)
{
AHCIPortRegs *pr = &ad->port_regs;
+ bool cmd_start = pr->cmd & PORT_CMD_START;
+ bool cmd_on = pr->cmd & PORT_CMD_LIST_ON;
+ bool fis_start = pr->cmd & PORT_CMD_FIS_RX;
+ bool fis_on = pr->cmd & PORT_CMD_FIS_ON;
- if (pr->cmd & PORT_CMD_START) {
+ if (cmd_start && !cmd_on) {
if (!ahci_map_clb_address(ad)) {
+ pr->cmd &= ~PORT_CMD_START;
error_report("AHCI: Failed to start DMA engine: "
"bad command list buffer address");
return -1;
}
- } else if (pr->cmd & PORT_CMD_LIST_ON) {
- if (allow_stop) {
- ahci_unmap_clb_address(ad);
- }
+ } else if (!cmd_start && cmd_on) {
+ ahci_unmap_clb_address(ad);
}
- if (pr->cmd & PORT_CMD_FIS_RX) {
+ if (fis_start && !fis_on) {
if (!ahci_map_fis_address(ad)) {
+ pr->cmd &= ~PORT_CMD_FIS_RX;
error_report("AHCI: Failed to start FIS receive engine: "
"bad FIS receive buffer address");
return -1;
}
- } else if (pr->cmd & PORT_CMD_FIS_ON) {
- if (allow_stop) {
- ahci_unmap_fis_address(ad);
- }
+ } else if (!fis_start && fis_on) {
+ ahci_unmap_fis_address(ad);
}
return 0;
@@ -272,8 +272,8 @@ static void ahci_port_write(AHCIState *s, int port, int
offset, uint32_t val)
pr->cmd = (pr->cmd & PORT_CMD_RO_MASK) |
(val & ~(PORT_CMD_RO_MASK|PORT_CMD_ICC_MASK));
- /* Check FIS RX and CLB engines, allow transition to false: */
- ahci_cond_start_engines(&s->dev[port], true);
+ /* Check FIS RX and CLB engines */
+ ahci_cond_start_engines(&s->dev[port]);
/* XXX usually the FIS would be pending on the bus here and
issuing deferred until the OS enables FIS receival.
@@ -1578,9 +1578,10 @@ static int ahci_state_post_load(void *opaque, int
version_id)
return -1;
}
- /* Only remap the CLB address if appropriate, disallowing a state
- * transition from 'on' to 'off' it should be consistent here. */
- if (ahci_cond_start_engines(ad, false) != 0) {
+ /* After a migrate, the DMA/FIS engines are "off" and
+ * need to be conditionally restarted */
+ pr->cmd &= ~(PORT_CMD_LIST_ON | PORT_CMD_FIS_ON);
+ if (ahci_cond_start_engines(ad) != 0) {
return -1;
}
--
2.4.3
- Re: [Qemu-devel] [PULL 00/11] Ide patches, (continued)
- [Qemu-devel] [PULL 03/11] ide: move buffered DMA cancel to core, John Snow, 2016/02/10
- [Qemu-devel] [PULL 04/11] ide: replace blk_drain_all by blk_drain, John Snow, 2016/02/10
- [Qemu-devel] [PULL 02/11] ide: code motion, John Snow, 2016/02/10
- [Qemu-devel] [PULL 05/11] ide: Add silent DRQ cancellation, John Snow, 2016/02/10
- [Qemu-devel] [PULL 06/11] ide: fix device_reset to not ignore pending AIO, John Snow, 2016/02/10
- [Qemu-devel] [PULL 07/11] fdc: always compile-check debug prints, John Snow, 2016/02/10
- [Qemu-devel] [PULL 10/11] ahci: explicitly reject bad engine states on post_load, John Snow, 2016/02/10
- [Qemu-devel] [PULL 08/11] ahci: Do not unmap NULL addresses, John Snow, 2016/02/10
- [Qemu-devel] [PULL 09/11] ahci: handle LIST_ON and FIS_ON in map helpers, John Snow, 2016/02/10
- [Qemu-devel] [PULL 11/11] ahci: prohibit "restarting" the FIS or CLB engines,
John Snow <=