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Diffstat (limited to 'docs/specs/vmw_pvscsi-spec.txt')
| -rw-r--r-- | docs/specs/vmw_pvscsi-spec.txt | 92 |
1 files changed, 0 insertions, 92 deletions
diff --git a/docs/specs/vmw_pvscsi-spec.txt b/docs/specs/vmw_pvscsi-spec.txt deleted file mode 100644 index 49affb2a42..0000000000 --- a/docs/specs/vmw_pvscsi-spec.txt +++ /dev/null @@ -1,92 +0,0 @@ -General Description -=================== - -This document describes VMWare PVSCSI device interface specification. -Created by Dmitry Fleytman (dmitry@daynix.com), Daynix Computing LTD. -Based on source code of PVSCSI Linux driver from kernel 3.0.4 - -PVSCSI Device Interface Overview -================================ - -The interface is based on memory area shared between hypervisor and VM. -Memory area is obtained by driver as device IO memory resource of -PVSCSI_MEM_SPACE_SIZE length. -The shared memory consists of registers area and rings area. -The registers area is used to raise hypervisor interrupts and issue device -commands. The rings area is used to transfer data descriptors and SCSI -commands from VM to hypervisor and to transfer messages produced by -hypervisor to VM. Data itself is transferred via virtual scatter-gather DMA. - -PVSCSI Device Registers -======================= - -The length of the registers area is 1 page (PVSCSI_MEM_SPACE_COMMAND_NUM_PAGES). -The structure of the registers area is described by the PVSCSIRegOffset enum. -There are registers to issue device command (with optional short data), -issue device interrupt, control interrupts masking. - -PVSCSI Device Rings -=================== - -There are three rings in shared memory: - - 1. Request ring (struct PVSCSIRingReqDesc *req_ring) - - ring for OS to device requests - 2. Completion ring (struct PVSCSIRingCmpDesc *cmp_ring) - - ring for device request completions - 3. Message ring (struct PVSCSIRingMsgDesc *msg_ring) - - ring for messages from device. - This ring is optional and the guest might not configure it. -There is a control area (struct PVSCSIRingsState *rings_state) used to control -rings operation. - -PVSCSI Device to Host Interrupts -================================ -There are following interrupt types supported by PVSCSI device: - 1. Completion interrupts (completion ring notifications): - PVSCSI_INTR_CMPL_0 - PVSCSI_INTR_CMPL_1 - 2. Message interrupts (message ring notifications): - PVSCSI_INTR_MSG_0 - PVSCSI_INTR_MSG_1 - -Interrupts are controlled via PVSCSI_REG_OFFSET_INTR_MASK register -Bit set means interrupt enabled, bit cleared - disabled - -Interrupt modes supported are legacy, MSI and MSI-X -In case of legacy interrupts, register PVSCSI_REG_OFFSET_INTR_STATUS -is used to check which interrupt has arrived. Interrupts are -acknowledged when the corresponding bit is written to the interrupt -status register. - -PVSCSI Device Operation Sequences -================================= - -1. Startup sequence: - a. Issue PVSCSI_CMD_ADAPTER_RESET command; - aa. Windows driver reads interrupt status register here; - b. Issue PVSCSI_CMD_SETUP_MSG_RING command with no additional data, - check status and disable device messages if error returned; - (Omitted if device messages disabled by driver configuration) - c. Issue PVSCSI_CMD_SETUP_RINGS command, provide rings configuration - as struct PVSCSICmdDescSetupRings; - d. Issue PVSCSI_CMD_SETUP_MSG_RING command again, provide - rings configuration as struct PVSCSICmdDescSetupMsgRing; - e. Unmask completion and message (if device messages enabled) interrupts. - -2. Shutdown sequences - a. Mask interrupts; - b. Flush request ring using PVSCSI_REG_OFFSET_KICK_NON_RW_IO; - c. Issue PVSCSI_CMD_ADAPTER_RESET command. - -3. Send request - a. Fill next free request ring descriptor; - b. Issue PVSCSI_REG_OFFSET_KICK_RW_IO for R/W operations; - or PVSCSI_REG_OFFSET_KICK_NON_RW_IO for other operations. - -4. Abort command - a. Issue PVSCSI_CMD_ABORT_CMD command; - -5. Request completion processing - a. Upon completion interrupt arrival process completion - and message (if enabled) rings. |