Merge remote-tracking branch 'remotes/jnsnow/tags/ide-pull-request' into staging

# gpg: Signature made Fri Mar 27 22:19:31 2015 GMT using RSA key ID AAFC390E
# gpg: Good signature from "John Snow (John Huston) <jsnow@redhat.com>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: FAEB 9711 A12C F475 812F  18F2 88A9 064D 1835 61EB
#      Subkey fingerprint: F9B7 ABDB BCAC DF95 BE76  CBD0 7DEF 8106 AAFC 390E

* remotes/jnsnow/tags/ide-pull-request:
  AHCI: Protect cmd register
  AHCI: Do not (re)map FB/CLB buffers while not running

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 60 insertions, 18 deletions

diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index 7a223bede7..833fd45faf 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -51,6 +51,10 @@ static void ahci_write_fis_d2h(AHCIDevice *ad, uint8_t *cmd_fis);
 static void ahci_init_d2h(AHCIDevice *ad);
 static int ahci_dma_prepare_buf(IDEDMA *dma, int is_write);
 static void ahci_commit_buf(IDEDMA *dma, uint32_t tx_bytes);
+static bool ahci_map_clb_address(AHCIDevice *ad);
+static bool ahci_map_fis_address(AHCIDevice *ad);
+static void ahci_unmap_clb_address(AHCIDevice *ad);
+static void ahci_unmap_fis_address(AHCIDevice *ad);
 
 
 static uint32_t  ahci_port_read(AHCIState *s, int port, int offset)
@@ -202,25 +206,15 @@ static void  ahci_port_write(AHCIState *s, int port, int offset, uint32_t val)
     switch (offset) {
         case PORT_LST_ADDR:
             pr->lst_addr = val;
-            map_page(s->as, &s->dev[port].lst,
-                     ((uint64_t)pr->lst_addr_hi << 32) | pr->lst_addr, 1024);
-            s->dev[port].cur_cmd = NULL;
             break;
         case PORT_LST_ADDR_HI:
             pr->lst_addr_hi = val;
-            map_page(s->as, &s->dev[port].lst,
-                     ((uint64_t)pr->lst_addr_hi << 32) | pr->lst_addr, 1024);
-            s->dev[port].cur_cmd = NULL;
             break;
         case PORT_FIS_ADDR:
             pr->fis_addr = val;
-            map_page(s->as, &s->dev[port].res_fis,
-                     ((uint64_t)pr->fis_addr_hi << 32) | pr->fis_addr, 256);
             break;
         case PORT_FIS_ADDR_HI:
             pr->fis_addr_hi = val;
-            map_page(s->as, &s->dev[port].res_fis,
-                     ((uint64_t)pr->fis_addr_hi << 32) | pr->fis_addr, 256);
             break;
         case PORT_IRQ_STAT:
             pr->irq_stat &= ~val;
@@ -231,14 +225,32 @@ static void  ahci_port_write(AHCIState *s, int port, int offset, uint32_t val)
             ahci_check_irq(s);
             break;
         case PORT_CMD:
-            pr->cmd = val & ~(PORT_CMD_LIST_ON | PORT_CMD_FIS_ON);
+            /* Block any Read-only fields from being set;
+             * including LIST_ON and FIS_ON. */
+            pr->cmd = (pr->cmd & PORT_CMD_RO_MASK) | (val & ~PORT_CMD_RO_MASK);
 
             if (pr->cmd & PORT_CMD_START) {
-                pr->cmd |= PORT_CMD_LIST_ON;
+                if (ahci_map_clb_address(&s->dev[port])) {
+                    pr->cmd |= PORT_CMD_LIST_ON;
+                } else {
+                    error_report("AHCI: Failed to start DMA engine: "
+                                 "bad command list buffer address");
+                }
+            } else if (pr->cmd & PORT_CMD_LIST_ON) {
+                ahci_unmap_clb_address(&s->dev[port]);
+                pr->cmd = pr->cmd & ~(PORT_CMD_LIST_ON);
             }
 
             if (pr->cmd & PORT_CMD_FIS_RX) {
-                pr->cmd |= PORT_CMD_FIS_ON;
+                if (ahci_map_fis_address(&s->dev[port])) {
+                    pr->cmd |= PORT_CMD_FIS_ON;
+                } else {
+                    error_report("AHCI: Failed to start FIS receive engine: "
+                                 "bad FIS receive buffer address");
+                }
+            } else if (pr->cmd & PORT_CMD_FIS_ON) {
+                ahci_unmap_fis_address(&s->dev[port]);
+                pr->cmd = pr->cmd & ~(PORT_CMD_FIS_ON);
             }
 
             /* XXX usually the FIS would be pending on the bus here and
@@ -565,6 +577,37 @@ static void debug_print_fis(uint8_t *fis, int cmd_len)
 #endif
 }
 
+static bool ahci_map_fis_address(AHCIDevice *ad)
+{
+    AHCIPortRegs *pr = &ad->port_regs;
+    map_page(ad->hba->as, &ad->res_fis,
+             ((uint64_t)pr->fis_addr_hi << 32) | pr->fis_addr, 256);
+    return ad->res_fis != NULL;
+}
+
+static void ahci_unmap_fis_address(AHCIDevice *ad)
+{
+    dma_memory_unmap(ad->hba->as, ad->res_fis, 256,
+                     DMA_DIRECTION_FROM_DEVICE, 256);
+    ad->res_fis = NULL;
+}
+
+static bool ahci_map_clb_address(AHCIDevice *ad)
+{
+    AHCIPortRegs *pr = &ad->port_regs;
+    ad->cur_cmd = NULL;
+    map_page(ad->hba->as, &ad->lst,
+             ((uint64_t)pr->lst_addr_hi << 32) | pr->lst_addr, 1024);
+    return ad->lst != NULL;
+}
+
+static void ahci_unmap_clb_address(AHCIDevice *ad)
+{
+    dma_memory_unmap(ad->hba->as, ad->lst, 1024,
+                     DMA_DIRECTION_FROM_DEVICE, 1024);
+    ad->lst = NULL;
+}
+
 static void ahci_write_fis_sdb(AHCIState *s, int port, uint32_t finished)
 {
     AHCIDevice *ad = &s->dev[port];
@@ -1360,12 +1403,9 @@ static int ahci_state_post_load(void *opaque, int version_id)
 
     for (i = 0; i < s->ports; i++) {
         ad = &s->dev[i];
-        AHCIPortRegs *pr = &ad->port_regs;
 
-        map_page(s->as, &ad->lst,
-                 ((uint64_t)pr->lst_addr_hi << 32) | pr->lst_addr, 1024);
-        map_page(s->as, &ad->res_fis,
-                 ((uint64_t)pr->fis_addr_hi << 32) | pr->fis_addr, 256);
+        ahci_map_clb_address(ad);
+        ahci_map_fis_address(ad);
         /*
          * If an error is present, ad->busy_slot will be valid and not -1.
          * In this case, an operation is waiting to resume and will re-check
diff --git a/hw/ide/ahci.h b/hw/ide/ahci.h
index 99aa0c967f..501c002c31 100644
--- a/hw/ide/ahci.h
+++ b/hw/ide/ahci.h
@@ -132,6 +132,8 @@
 #define PORT_CMD_ICC_PARTIAL      (0x2 << 28) /* Put i/f in partial state */
 #define PORT_CMD_ICC_SLUMBER      (0x6 << 28) /* Put i/f in slumber state */
 
+#define PORT_CMD_RO_MASK          0x007dffe0 /* Which CMD bits are read only? */
+
 /* ap->flags bits */
 #define AHCI_FLAG_NO_NCQ                  (1 << 24)
 #define AHCI_FLAG_IGN_IRQ_IF_ERR          (1 << 25) /* ignore IRQ_IF_ERR */