| Message ID | 20210827172114.414281-13-ltykernel@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | x86/Hyper-V: Add Hyper-V Isolation VM support | expand |
From: Tianyu Lan <ltykernel@gmail.com> Sent: Friday, August 27, 2021 10:21 AM > > 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_ > pagebuffer() stills need to be handled. Use DMA API to map/umap > these memory during sending/receiving packet and Hyper-V swiotlb > bounce buffer dma adress will be returned. The swiotlb bounce buffer > has been masked to be visible to host during boot up. > > Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> > --- > Change since v3: > * Add comment to explain why not to use dma_map_sg() > * Fix some error handle. > --- > arch/x86/hyperv/ivm.c | 1 + > drivers/net/hyperv/hyperv_net.h | 5 ++ > drivers/net/hyperv/netvsc.c | 135 +++++++++++++++++++++++++++++- > drivers/net/hyperv/rndis_filter.c | 2 + > include/linux/hyperv.h | 5 ++ > 5 files changed, 145 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c > index 84563b3c9f3a..08d8e01de017 100644 > --- a/arch/x86/hyperv/ivm.c > +++ b/arch/x86/hyperv/ivm.c > @@ -317,6 +317,7 @@ void *hv_map_memory(void *addr, unsigned long size) > > return vaddr; > } > +EXPORT_SYMBOL_GPL(hv_map_memory); > > void hv_unmap_memory(void *addr) > { > diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h > index aa7c9962dbd8..862419912bfb 100644 > --- a/drivers/net/hyperv/hyperv_net.h > +++ b/drivers/net/hyperv/hyperv_net.h > @@ -164,6 +164,7 @@ struct hv_netvsc_packet { > u32 total_bytes; > u32 send_buf_index; > u32 total_data_buflen; > + struct hv_dma_range *dma_range; > }; > > #define NETVSC_HASH_KEYLEN 40 > @@ -1074,6 +1075,7 @@ struct netvsc_device { > > /* Receive buffer allocated by us but manages by NetVSP */ > void *recv_buf; > + void *recv_original_buf; > u32 recv_buf_size; /* allocated bytes */ > u32 recv_buf_gpadl_handle; > u32 recv_section_cnt; > @@ -1082,6 +1084,7 @@ struct netvsc_device { > > /* Send buffer allocated by us */ > void *send_buf; > + void *send_original_buf; > u32 send_buf_size; > u32 send_buf_gpadl_handle; > u32 send_section_cnt; > @@ -1731,4 +1734,6 @@ struct rndis_message { > #define RETRY_US_HI 10000 > #define RETRY_MAX 2000 /* >10 sec */ > > +void netvsc_dma_unmap(struct hv_device *hv_dev, > + struct hv_netvsc_packet *packet); > #endif /* _HYPERV_NET_H */ > diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c > index f19bffff6a63..edd336b08c2c 100644 > --- a/drivers/net/hyperv/netvsc.c > +++ b/drivers/net/hyperv/netvsc.c > @@ -153,8 +153,21 @@ static void free_netvsc_device(struct rcu_head *head) > int i; > > kfree(nvdev->extension); > - vfree(nvdev->recv_buf); > - vfree(nvdev->send_buf); > + > + if (nvdev->recv_original_buf) { > + vunmap(nvdev->recv_buf); In patch 11, you have added a hv_unmap_memory() function as the inverse of hv_map_memory(). Since this buffer was mapped with hv_map_memory() and you have added that function, the cleanup should use hv_unmap_memory() rather than calling vunmap() directly. > + vfree(nvdev->recv_original_buf); > + } else { > + vfree(nvdev->recv_buf); > + } > + > + if (nvdev->send_original_buf) { > + vunmap(nvdev->send_buf); Same here. > + vfree(nvdev->send_original_buf); > + } else { > + vfree(nvdev->send_buf); > + } > + > kfree(nvdev->send_section_map); > > for (i = 0; i < VRSS_CHANNEL_MAX; i++) { > @@ -347,6 +360,7 @@ static int netvsc_init_buf(struct hv_device *device, > unsigned int buf_size; > size_t map_words; > int i, ret = 0; > + void *vaddr; > > /* Get receive buffer area. */ > buf_size = device_info->recv_sections * device_info->recv_section_size; > @@ -382,6 +396,17 @@ static int netvsc_init_buf(struct hv_device *device, > goto cleanup; > } > > + if (hv_isolation_type_snp()) { > + vaddr = hv_map_memory(net_device->recv_buf, buf_size); Since the netvsc driver is architecture neutral, this code also needs to compile for ARM64. A stub will be needed for hv_map_memory() on the ARM64 side. Same for hv_unmap_memory() as suggested above. Or better, move hv_map_memory() and hv_unmap_memory() to an architecture neutral module such as hv_common.c. Or if Christop's approach of creating the vmap_phys_addr() helper comes to fruition, that's an even better approach since it will already handle multiple architectures. > + if (!vaddr) { > + ret = -ENOMEM; > + goto cleanup; > + } > + > + net_device->recv_original_buf = net_device->recv_buf; > + net_device->recv_buf = vaddr; > + } > + > /* Notify the NetVsp of the gpadl handle */ > init_packet = &net_device->channel_init_pkt; > memset(init_packet, 0, sizeof(struct nvsp_message)); > @@ -485,6 +510,17 @@ static int netvsc_init_buf(struct hv_device *device, > goto cleanup; > } > > + if (hv_isolation_type_snp()) { > + vaddr = hv_map_memory(net_device->send_buf, buf_size); > + if (!vaddr) { > + ret = -ENOMEM; > + goto cleanup; > + } > + > + net_device->send_original_buf = net_device->send_buf; > + net_device->send_buf = vaddr; > + } > + > /* Notify the NetVsp of the gpadl handle */ > init_packet = &net_device->channel_init_pkt; > memset(init_packet, 0, sizeof(struct nvsp_message)); > @@ -775,7 +811,7 @@ static void netvsc_send_tx_complete(struct net_device *ndev, > > /* Notify the layer above us */ > if (likely(skb)) { > - const struct hv_netvsc_packet *packet > + struct hv_netvsc_packet *packet > = (struct hv_netvsc_packet *)skb->cb; > u32 send_index = packet->send_buf_index; > struct netvsc_stats *tx_stats; > @@ -791,6 +827,7 @@ static void netvsc_send_tx_complete(struct net_device *ndev, > tx_stats->bytes += packet->total_bytes; > u64_stats_update_end(&tx_stats->syncp); > > + netvsc_dma_unmap(ndev_ctx->device_ctx, packet); > napi_consume_skb(skb, budget); > } > > @@ -955,6 +992,87 @@ static void netvsc_copy_to_send_buf(struct netvsc_device *net_device, > memset(dest, 0, padding); > } > > +void netvsc_dma_unmap(struct hv_device *hv_dev, > + struct hv_netvsc_packet *packet) > +{ > + u32 page_count = packet->cp_partial ? > + packet->page_buf_cnt - packet->rmsg_pgcnt : > + packet->page_buf_cnt; > + int i; > + > + if (!hv_is_isolation_supported()) > + return; > + > + if (!packet->dma_range) > + return; > + > + for (i = 0; i < page_count; i++) > + dma_unmap_single(&hv_dev->device, packet->dma_range[i].dma, > + packet->dma_range[i].mapping_size, > + DMA_TO_DEVICE); > + > + kfree(packet->dma_range); > +} > + > +/* netvsc_dma_map - Map swiotlb bounce buffer with data page of > + * packet sent by vmbus_sendpacket_pagebuffer() in the Isolation > + * VM. > + * > + * In isolation VM, netvsc send buffer has been marked visible to > + * host and so the data copied to send buffer doesn't need to use > + * bounce buffer. The data pages handled by vmbus_sendpacket_pagebuffer() > + * may not be copied to send buffer and so these pages need to be > + * mapped with swiotlb bounce buffer. netvsc_dma_map() is to do > + * that. The pfns in the struct hv_page_buffer need to be converted > + * to bounce buffer's pfn. The loop here is necessary becuase the s/becuase/because/ > + * entries in the page buffer array are not necessarily full > + * pages of data. Each entry in the array has a separate offset and > + * len that may be non-zero, even for entries in the middle of the > + * array. And the entries are not physically contiguous. So each > + * entry must be individually mapped rather than as a contiguous unit. > + * So not use dma_map_sg() here. > + */ > +int netvsc_dma_map(struct hv_device *hv_dev, > + struct hv_netvsc_packet *packet, > + struct hv_page_buffer *pb) > +{ > + u32 page_count = packet->cp_partial ? > + packet->page_buf_cnt - packet->rmsg_pgcnt : > + packet->page_buf_cnt; > + dma_addr_t dma; > + int i; > + > + if (!hv_is_isolation_supported()) > + return 0; > + > + packet->dma_range = kcalloc(page_count, > + sizeof(*packet->dma_range), > + GFP_KERNEL); > + if (!packet->dma_range) > + return -ENOMEM; > + > + for (i = 0; i < page_count; i++) { > + char *src = phys_to_virt((pb[i].pfn << HV_HYP_PAGE_SHIFT) > + + pb[i].offset); > + u32 len = pb[i].len; > + > + dma = dma_map_single(&hv_dev->device, src, len, > + DMA_TO_DEVICE); > + if (dma_mapping_error(&hv_dev->device, dma)) { > + kfree(packet->dma_range); > + return -ENOMEM; > + } > + > + packet->dma_range[i].dma = dma; > + packet->dma_range[i].mapping_size = len; > + pb[i].pfn = dma >> HV_HYP_PAGE_SHIFT; > + pb[i].offset = offset_in_hvpage(dma); > + pb[i].len = len; > + } Just to confirm, this driver does *not* set the DMA min_align_mask like storvsc does. So after the call to dma_map_single(), the offset in the page could be different. That's why you are updating the pb[i].offset value. Alternatively, you could set the DMA min_align_mask, which would ensure the offset is unchanged. I'm OK with either approach, though perhaps a comment is warranted to explain, as this is a subtle issue. > + > + return 0; > +} > + > static inline int netvsc_send_pkt( > struct hv_device *device, > struct hv_netvsc_packet *packet, > @@ -995,14 +1113,24 @@ static inline int netvsc_send_pkt( > > trace_nvsp_send_pkt(ndev, out_channel, rpkt); > > + packet->dma_range = NULL; > if (packet->page_buf_cnt) { > if (packet->cp_partial) > pb += packet->rmsg_pgcnt; > > + ret = netvsc_dma_map(ndev_ctx->device_ctx, packet, pb); > + if (ret) { > + ret = -EAGAIN; > + goto exit; > + } > + > ret = vmbus_sendpacket_pagebuffer(out_channel, > pb, packet->page_buf_cnt, > &nvmsg, sizeof(nvmsg), > req_id); > + > + if (ret) > + netvsc_dma_unmap(ndev_ctx->device_ctx, packet); > } else { > ret = vmbus_sendpacket(out_channel, > &nvmsg, sizeof(nvmsg), > @@ -1010,6 +1138,7 @@ static inline int netvsc_send_pkt( > VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); > } > > +exit: > if (ret == 0) { > atomic_inc_return(&nvchan->queue_sends); > > diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c > index f6c9c2a670f9..448fcc325ed7 100644 > --- a/drivers/net/hyperv/rndis_filter.c > +++ b/drivers/net/hyperv/rndis_filter.c > @@ -361,6 +361,8 @@ static void rndis_filter_receive_response(struct net_device *ndev, > } > } > > + netvsc_dma_unmap(((struct net_device_context *) > + netdev_priv(ndev))->device_ctx, &request->pkt); > complete(&request->wait_event); > } else { > netdev_err(ndev, > diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h > index 724a735d722a..139a43ad65a1 100644 > --- a/include/linux/hyperv.h > +++ b/include/linux/hyperv.h > @@ -1596,6 +1596,11 @@ struct hyperv_service_callback { > void (*callback)(void *context); > }; > > +struct hv_dma_range { > + dma_addr_t dma; > + u32 mapping_size; > +}; > + > #define MAX_SRV_VER 0x7ffffff > extern bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, u8 *buf, u32 buflen, > const int *fw_version, int fw_vercnt, > -- > 2.25.1
From: Michael Kelley <mikelley@microsoft.com> Sent: Wednesday, September 1, 2021 7:34 PM [snip] > > +int netvsc_dma_map(struct hv_device *hv_dev, > > + struct hv_netvsc_packet *packet, > > + struct hv_page_buffer *pb) > > +{ > > + u32 page_count = packet->cp_partial ? > > + packet->page_buf_cnt - packet->rmsg_pgcnt : > > + packet->page_buf_cnt; > > + dma_addr_t dma; > > + int i; > > + > > + if (!hv_is_isolation_supported()) > > + return 0; > > + > > + packet->dma_range = kcalloc(page_count, > > + sizeof(*packet->dma_range), > > + GFP_KERNEL); > > + if (!packet->dma_range) > > + return -ENOMEM; > > + > > + for (i = 0; i < page_count; i++) { > > + char *src = phys_to_virt((pb[i].pfn << HV_HYP_PAGE_SHIFT) > > + + pb[i].offset); > > + u32 len = pb[i].len; > > + > > + dma = dma_map_single(&hv_dev->device, src, len, > > + DMA_TO_DEVICE); > > + if (dma_mapping_error(&hv_dev->device, dma)) { > > + kfree(packet->dma_range); > > + return -ENOMEM; > > + } > > + > > + packet->dma_range[i].dma = dma; > > + packet->dma_range[i].mapping_size = len; > > + pb[i].pfn = dma >> HV_HYP_PAGE_SHIFT; > > + pb[i].offset = offset_in_hvpage(dma); > > + pb[i].len = len; > > + } > > Just to confirm, this driver does *not* set the DMA min_align_mask > like storvsc does. So after the call to dma_map_single(), the offset > in the page could be different. That's why you are updating > the pb[i].offset value. Alternatively, you could set the DMA > min_align_mask, which would ensure the offset is unchanged. > I'm OK with either approach, though perhaps a comment is > warranted to explain, as this is a subtle issue. > On second thought, I don't think either approach is OK. The default alignment in the swiotlb is 2K, and if the length of the data in the buffer was 3K, the data could cross a page boundary in the bounce buffer when it originally did not. This would break the above code which can only deal with one page at a time. So I think the netvsc driver also must set the DMA min_align_mask to 4K, which will preserve the offset. Michael
diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c index 84563b3c9f3a..08d8e01de017 100644 --- a/arch/x86/hyperv/ivm.c +++ b/arch/x86/hyperv/ivm.c @@ -317,6 +317,7 @@ void *hv_map_memory(void *addr, unsigned long size) return vaddr; } +EXPORT_SYMBOL_GPL(hv_map_memory); void hv_unmap_memory(void *addr) { diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h index aa7c9962dbd8..862419912bfb 100644 --- a/drivers/net/hyperv/hyperv_net.h +++ b/drivers/net/hyperv/hyperv_net.h @@ -164,6 +164,7 @@ struct hv_netvsc_packet { u32 total_bytes; u32 send_buf_index; u32 total_data_buflen; + struct hv_dma_range *dma_range; }; #define NETVSC_HASH_KEYLEN 40 @@ -1074,6 +1075,7 @@ struct netvsc_device { /* Receive buffer allocated by us but manages by NetVSP */ void *recv_buf; + void *recv_original_buf; u32 recv_buf_size; /* allocated bytes */ u32 recv_buf_gpadl_handle; u32 recv_section_cnt; @@ -1082,6 +1084,7 @@ struct netvsc_device { /* Send buffer allocated by us */ void *send_buf; + void *send_original_buf; u32 send_buf_size; u32 send_buf_gpadl_handle; u32 send_section_cnt; @@ -1731,4 +1734,6 @@ struct rndis_message { #define RETRY_US_HI 10000 #define RETRY_MAX 2000 /* >10 sec */ +void netvsc_dma_unmap(struct hv_device *hv_dev, + struct hv_netvsc_packet *packet); #endif /* _HYPERV_NET_H */ diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index f19bffff6a63..edd336b08c2c 100644 --- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c @@ -153,8 +153,21 @@ static void free_netvsc_device(struct rcu_head *head) int i; kfree(nvdev->extension); - vfree(nvdev->recv_buf); - vfree(nvdev->send_buf); + + if (nvdev->recv_original_buf) { + vunmap(nvdev->recv_buf); + vfree(nvdev->recv_original_buf); + } else { + vfree(nvdev->recv_buf); + } + + if (nvdev->send_original_buf) { + vunmap(nvdev->send_buf); + vfree(nvdev->send_original_buf); + } else { + vfree(nvdev->send_buf); + } + kfree(nvdev->send_section_map); for (i = 0; i < VRSS_CHANNEL_MAX; i++) { @@ -347,6 +360,7 @@ static int netvsc_init_buf(struct hv_device *device, unsigned int buf_size; size_t map_words; int i, ret = 0; + void *vaddr; /* Get receive buffer area. */ buf_size = device_info->recv_sections * device_info->recv_section_size; @@ -382,6 +396,17 @@ static int netvsc_init_buf(struct hv_device *device, goto cleanup; } + if (hv_isolation_type_snp()) { + vaddr = hv_map_memory(net_device->recv_buf, buf_size); + if (!vaddr) { + ret = -ENOMEM; + goto cleanup; + } + + net_device->recv_original_buf = net_device->recv_buf; + net_device->recv_buf = vaddr; + } + /* Notify the NetVsp of the gpadl handle */ init_packet = &net_device->channel_init_pkt; memset(init_packet, 0, sizeof(struct nvsp_message)); @@ -485,6 +510,17 @@ static int netvsc_init_buf(struct hv_device *device, goto cleanup; } + if (hv_isolation_type_snp()) { + vaddr = hv_map_memory(net_device->send_buf, buf_size); + if (!vaddr) { + ret = -ENOMEM; + goto cleanup; + } + + net_device->send_original_buf = net_device->send_buf; + net_device->send_buf = vaddr; + } + /* Notify the NetVsp of the gpadl handle */ init_packet = &net_device->channel_init_pkt; memset(init_packet, 0, sizeof(struct nvsp_message)); @@ -775,7 +811,7 @@ static void netvsc_send_tx_complete(struct net_device *ndev, /* Notify the layer above us */ if (likely(skb)) { - const struct hv_netvsc_packet *packet + struct hv_netvsc_packet *packet = (struct hv_netvsc_packet *)skb->cb; u32 send_index = packet->send_buf_index; struct netvsc_stats *tx_stats; @@ -791,6 +827,7 @@ static void netvsc_send_tx_complete(struct net_device *ndev, tx_stats->bytes += packet->total_bytes; u64_stats_update_end(&tx_stats->syncp); + netvsc_dma_unmap(ndev_ctx->device_ctx, packet); napi_consume_skb(skb, budget); } @@ -955,6 +992,87 @@ static void netvsc_copy_to_send_buf(struct netvsc_device *net_device, memset(dest, 0, padding); } +void netvsc_dma_unmap(struct hv_device *hv_dev, + struct hv_netvsc_packet *packet) +{ + u32 page_count = packet->cp_partial ? + packet->page_buf_cnt - packet->rmsg_pgcnt : + packet->page_buf_cnt; + int i; + + if (!hv_is_isolation_supported()) + return; + + if (!packet->dma_range) + return; + + for (i = 0; i < page_count; i++) + dma_unmap_single(&hv_dev->device, packet->dma_range[i].dma, + packet->dma_range[i].mapping_size, + DMA_TO_DEVICE); + + kfree(packet->dma_range); +} + +/* netvsc_dma_map - Map swiotlb bounce buffer with data page of + * packet sent by vmbus_sendpacket_pagebuffer() in the Isolation + * VM. + * + * In isolation VM, netvsc send buffer has been marked visible to + * host and so the data copied to send buffer doesn't need to use + * bounce buffer. The data pages handled by vmbus_sendpacket_pagebuffer() + * may not be copied to send buffer and so these pages need to be + * mapped with swiotlb bounce buffer. netvsc_dma_map() is to do + * that. The pfns in the struct hv_page_buffer need to be converted + * to bounce buffer's pfn. The loop here is necessary becuase the + * entries in the page buffer array are not necessarily full + * pages of data. Each entry in the array has a separate offset and + * len that may be non-zero, even for entries in the middle of the + * array. And the entries are not physically contiguous. So each + * entry must be individually mapped rather than as a contiguous unit. + * So not use dma_map_sg() here. + */ +int netvsc_dma_map(struct hv_device *hv_dev, + struct hv_netvsc_packet *packet, + struct hv_page_buffer *pb) +{ + u32 page_count = packet->cp_partial ? + packet->page_buf_cnt - packet->rmsg_pgcnt : + packet->page_buf_cnt; + dma_addr_t dma; + int i; + + if (!hv_is_isolation_supported()) + return 0; + + packet->dma_range = kcalloc(page_count, + sizeof(*packet->dma_range), + GFP_KERNEL); + if (!packet->dma_range) + return -ENOMEM; + + for (i = 0; i < page_count; i++) { + char *src = phys_to_virt((pb[i].pfn << HV_HYP_PAGE_SHIFT) + + pb[i].offset); + u32 len = pb[i].len; + + dma = dma_map_single(&hv_dev->device, src, len, + DMA_TO_DEVICE); + if (dma_mapping_error(&hv_dev->device, dma)) { + kfree(packet->dma_range); + return -ENOMEM; + } + + packet->dma_range[i].dma = dma; + packet->dma_range[i].mapping_size = len; + pb[i].pfn = dma >> HV_HYP_PAGE_SHIFT; + pb[i].offset = offset_in_hvpage(dma); + pb[i].len = len; + } + + return 0; +} + static inline int netvsc_send_pkt( struct hv_device *device, struct hv_netvsc_packet *packet, @@ -995,14 +1113,24 @@ static inline int netvsc_send_pkt( trace_nvsp_send_pkt(ndev, out_channel, rpkt); + packet->dma_range = NULL; if (packet->page_buf_cnt) { if (packet->cp_partial) pb += packet->rmsg_pgcnt; + ret = netvsc_dma_map(ndev_ctx->device_ctx, packet, pb); + if (ret) { + ret = -EAGAIN; + goto exit; + } + ret = vmbus_sendpacket_pagebuffer(out_channel, pb, packet->page_buf_cnt, &nvmsg, sizeof(nvmsg), req_id); + + if (ret) + netvsc_dma_unmap(ndev_ctx->device_ctx, packet); } else { ret = vmbus_sendpacket(out_channel, &nvmsg, sizeof(nvmsg), @@ -1010,6 +1138,7 @@ static inline int netvsc_send_pkt( VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); } +exit: if (ret == 0) { atomic_inc_return(&nvchan->queue_sends); diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c index f6c9c2a670f9..448fcc325ed7 100644 --- a/drivers/net/hyperv/rndis_filter.c +++ b/drivers/net/hyperv/rndis_filter.c @@ -361,6 +361,8 @@ static void rndis_filter_receive_response(struct net_device *ndev, } } + netvsc_dma_unmap(((struct net_device_context *) + netdev_priv(ndev))->device_ctx, &request->pkt); complete(&request->wait_event); } else { netdev_err(ndev, diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 724a735d722a..139a43ad65a1 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1596,6 +1596,11 @@ struct hyperv_service_callback { void (*callback)(void *context); }; +struct hv_dma_range { + dma_addr_t dma; + u32 mapping_size; +}; + #define MAX_SRV_VER 0x7ffffff extern bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, u8 *buf, u32 buflen, const int *fw_version, int fw_vercnt,