diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 3fb7e8b..e330c26 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -3035,15 +3035,20 @@
 	}
 #endif
 
-	/* Disabling DMA prefetch for the P600
-	 * An ASIC bug may result in a prefetch beyond
-	 * physical memory.
+	/* Disabling DMA prefetch and refetch for the P600.
+	 * An ASIC bug may result in accesses to invalid memory addresses.
+	 * We've disabled prefetch for some time now. Testing with XEN
+	 * kernels revealed a bug in the refetch if dom0 resides on a P600.
 	 */
 	if(board_id == 0x3225103C) {
 		__u32 dma_prefetch;
+		__u32 dma_refetch;
 		dma_prefetch = readl(c->vaddr + I2O_DMA1_CFG);
 		dma_prefetch |= 0x8000;
 		writel(dma_prefetch, c->vaddr + I2O_DMA1_CFG);
+		pci_read_config_dword(pdev, PCI_COMMAND_PARITY, &dma_refetch);
+		dma_refetch |= 0x1;
+		pci_write_config_dword(pdev, PCI_COMMAND_PARITY, dma_refetch);
 	}
 
 #ifdef CCISS_DEBUG