Re: [Resend RFC PATCH V2 12/12] HV/Storvsc: Add Isolation VM support for storvsc driver

2021-04-14 Thread Christoph Hellwig
Same comments as for the net driver.  In addition to all the poking
into kernel internals the fact that this is duplicated in the two main
drivers should have been a huge red flag.


[Resend RFC PATCH V2 12/12] HV/Storvsc: Add Isolation VM support for storvsc driver

2021-04-14 Thread Tianyu Lan
From: Tianyu Lan 

In Isolation VM, all shared memory with host needs to mark visible
to host via hvcall. vmbus_establish_gpadl() has already done it for
netvsc rx/tx ring buffer. The page buffer used by vmbus_sendpacket_
mpb_desc() still need to handle. Use DMA API to map/umap these
memory during sending/receiving packet and Hyper-V DMA ops callback
will use swiotlb fucntion to allocate bounce buffer and copy data
from/to bounce buffer.

Signed-off-by: Tianyu Lan 
---
 drivers/scsi/storvsc_drv.c | 67 +-
 1 file changed, 66 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 2e4fa77445fd..d271578b1811 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -21,6 +21,8 @@
 #include 
 #include 
 #include 
+#include 
+#include 
 #include 
 #include 
 #include 
@@ -414,6 +416,11 @@ static void storvsc_on_channel_callback(void *context);
 #define STORVSC_IDE_MAX_TARGETS1
 #define STORVSC_IDE_MAX_CHANNELS   1
 
+struct dma_range {
+   dma_addr_t dma;
+   u32 mapping_size;
+};
+
 struct storvsc_cmd_request {
struct scsi_cmnd *cmd;
 
@@ -427,6 +434,8 @@ struct storvsc_cmd_request {
u32 payload_sz;
 
struct vstor_packet vstor_packet;
+   u32 hvpg_count;
+   struct dma_range *dma_range;
 };
 
 
@@ -1236,6 +1245,7 @@ static void storvsc_on_channel_callback(void *context)
const struct vmpacket_descriptor *desc;
struct hv_device *device;
struct storvsc_device *stor_device;
+   int i;
 
if (channel->primary_channel != NULL)
device = channel->primary_channel->device_obj;
@@ -1249,6 +1259,8 @@ static void storvsc_on_channel_callback(void *context)
foreach_vmbus_pkt(desc, channel) {
void *packet = hv_pkt_data(desc);
struct storvsc_cmd_request *request;
+   enum dma_data_direction dir;
+   u32 attrs;
u64 cmd_rqst;
 
cmd_rqst = vmbus_request_addr(>requestor,
@@ -1261,6 +1273,22 @@ static void storvsc_on_channel_callback(void *context)
 
request = (struct storvsc_cmd_request *)(unsigned long)cmd_rqst;
 
+   if (request->vstor_packet.vm_srb.data_in == READ_TYPE)
+   dir = DMA_FROM_DEVICE;
+else
+   dir = DMA_TO_DEVICE;
+
+   if (request->dma_range) {
+   for (i = 0; i < request->hvpg_count; i++)
+   dma_unmap_page_attrs(>device,
+   request->dma_range[i].dma,
+   
request->dma_range[i].mapping_size,
+   
request->vstor_packet.vm_srb.data_in
+== READ_TYPE ?
+   DMA_FROM_DEVICE : 
DMA_TO_DEVICE, attrs);
+   kfree(request->dma_range);
+   }
+
if (request == _device->init_request ||
request == _device->reset_request) {
memcpy(>vstor_packet, packet,
@@ -1682,8 +1710,10 @@ static int storvsc_queuecommand(struct Scsi_Host *host, 
struct scsi_cmnd *scmnd)
struct vmscsi_request *vm_srb;
struct scatterlist *cur_sgl;
struct vmbus_packet_mpb_array  *payload;
+   enum dma_data_direction dir;
u32 payload_sz;
u32 length;
+   u32 attrs;
 
if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
/*
@@ -1722,14 +1752,17 @@ static int storvsc_queuecommand(struct Scsi_Host *host, 
struct scsi_cmnd *scmnd)
case DMA_TO_DEVICE:
vm_srb->data_in = WRITE_TYPE;
vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
+   dir = DMA_TO_DEVICE;
break;
case DMA_FROM_DEVICE:
vm_srb->data_in = READ_TYPE;
vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
+   dir = DMA_FROM_DEVICE;
break;
case DMA_NONE:
vm_srb->data_in = UNKNOWN_TYPE;
vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
+   dir = DMA_NONE;
break;
default:
/*
@@ -1786,6 +1819,12 @@ static int storvsc_queuecommand(struct Scsi_Host *host, 
struct scsi_cmnd *scmnd)
hvpgoff = sgl->offset >> HV_HYP_PAGE_SHIFT;
 
cur_sgl = sgl;
+
+   cmd_request->dma_range = kzalloc(sizeof(struct dma_range) * 
hvpg_count,
+ GFP_ATOMIC);
+   if (!cmd_request->dma_range)
+   return -ENOMEM;
+
for (i = 0; i < hvpg_count; i++) {
/*
 * 'i' is the