Messages in this thread | | | Date | Thu, 9 Dec 2021 16:08:29 +0800 | Subject | Re: [PATCH V6 5/5] net: netvsc: Add Isolation VM support for netvsc driver | From | Tianyu Lan <> |
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On 12/9/2021 4:14 AM, Haiyang Zhang wrote: >> From: Tianyu Lan <ltykernel@gmail.com> >> Sent: Tuesday, December 7, 2021 2:56 AM >> To: KY Srinivasan <kys@microsoft.com>; Haiyang Zhang <haiyangz@microsoft.com>; Stephen >> Hemminger <sthemmin@microsoft.com>; wei.liu@kernel.org; Dexuan Cui <decui@microsoft.com>; >> tglx@linutronix.de; mingo@redhat.com; bp@alien8.de; dave.hansen@linux.intel.com; >> x86@kernel.org; hpa@zytor.com; davem@davemloft.net; kuba@kernel.org; jejb@linux.ibm.com; >> martin.petersen@oracle.com; arnd@arndb.de; hch@infradead.org; m.szyprowski@samsung.com; >> robin.murphy@arm.com; Tianyu Lan <Tianyu.Lan@microsoft.com>; thomas.lendacky@amd.com; >> Michael Kelley (LINUX) <mikelley@microsoft.com> >> Cc: iommu@lists.linux-foundation.org; linux-arch@vger.kernel.org; linux- >> hyperv@vger.kernel.org; linux-kernel@vger.kernel.org; linux-scsi@vger.kernel.org; >> netdev@vger.kernel.org; vkuznets <vkuznets@redhat.com>; brijesh.singh@amd.com; >> konrad.wilk@oracle.com; hch@lst.de; joro@8bytes.org; parri.andrea@gmail.com; >> dave.hansen@intel.com >> Subject: [PATCH V6 5/5] net: netvsc: Add Isolation VM support for netvsc driver >> >> From: Tianyu Lan <Tianyu.Lan@microsoft.com> >> >> 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 address will be returned. The swiotlb bounce buffer >> has been masked to be visible to host during boot up. >> >> rx/tx ring buffer is allocated via vzalloc() and they need to be >> mapped into unencrypted address space(above vTOM) before sharing >> with host and accessing. Add hv_map/unmap_memory() to map/umap rx >> /tx ring buffer. >> >> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> >> --- >> Change since v3: >> * Replace HV_HYP_PAGE_SIZE with PAGE_SIZE and virt_to_hvpfn() >> with vmalloc_to_pfn() in the hv_map_memory() >> >> Change since v2: >> * Add hv_map/unmap_memory() to map/umap rx/tx ring buffer. >> --- >> arch/x86/hyperv/ivm.c | 28 ++++++ >> drivers/hv/hv_common.c | 11 +++ >> drivers/net/hyperv/hyperv_net.h | 5 ++ >> drivers/net/hyperv/netvsc.c | 136 +++++++++++++++++++++++++++++- >> drivers/net/hyperv/netvsc_drv.c | 1 + >> drivers/net/hyperv/rndis_filter.c | 2 + >> include/asm-generic/mshyperv.h | 2 + >> include/linux/hyperv.h | 5 ++ >> 8 files changed, 187 insertions(+), 3 deletions(-) >> >> diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c >> index 69c7a57f3307..2b994117581e 100644 >> --- a/arch/x86/hyperv/ivm.c >> +++ b/arch/x86/hyperv/ivm.c >> @@ -287,3 +287,31 @@ int hv_set_mem_host_visibility(unsigned long kbuffer, int pagecount, >> bool visibl >> kfree(pfn_array); >> return ret; >> } >> + >> +/* >> + * hv_map_memory - map memory to extra space in the AMD SEV-SNP Isolation VM. >> + */ >> +void *hv_map_memory(void *addr, unsigned long size) >> +{ >> + unsigned long *pfns = kcalloc(size / PAGE_SIZE, >> + sizeof(unsigned long), GFP_KERNEL); >> + void *vaddr; >> + int i; >> + >> + if (!pfns) >> + return NULL; >> + >> + for (i = 0; i < size / PAGE_SIZE; i++) >> + pfns[i] = vmalloc_to_pfn(addr + i * PAGE_SIZE) + >> + (ms_hyperv.shared_gpa_boundary >> PAGE_SHIFT); >> + >> + vaddr = vmap_pfn(pfns, size / PAGE_SIZE, PAGE_KERNEL_IO); >> + kfree(pfns); >> + >> + return vaddr; >> +} >> + >> +void hv_unmap_memory(void *addr) >> +{ >> + vunmap(addr); >> +} >> diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c >> index 7be173a99f27..3c5cb1f70319 100644 >> --- a/drivers/hv/hv_common.c >> +++ b/drivers/hv/hv_common.c >> @@ -295,3 +295,14 @@ u64 __weak hv_ghcb_hypercall(u64 control, void *input, void *output, >> u32 input_s >> return HV_STATUS_INVALID_PARAMETER; >> } >> EXPORT_SYMBOL_GPL(hv_ghcb_hypercall); >> + >> +void __weak *hv_map_memory(void *addr, unsigned long size) >> +{ >> + return NULL; >> +} >> +EXPORT_SYMBOL_GPL(hv_map_memory); >> + >> +void __weak hv_unmap_memory(void *addr) >> +{ >> +} >> +EXPORT_SYMBOL_GPL(hv_unmap_memory); >> diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h >> index 315278a7cf88..cf69da0e296c 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 */ >> struct vmbus_gpadl 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; >> struct vmbus_gpadl 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 396bc1c204e6..b7ade735a806 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) { >> + hv_unmap_memory(nvdev->recv_buf); >> + vfree(nvdev->recv_original_buf); >> + } else { >> + vfree(nvdev->recv_buf); >> + } >> + >> + if (nvdev->send_original_buf) { >> + hv_unmap_memory(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++) { >> @@ -338,6 +351,7 @@ 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; >> @@ -373,6 +387,17 @@ 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)); >> @@ -476,6 +501,17 @@ 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)); >> @@ -766,7 +802,7 @@ 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; >> @@ -782,6 +818,7 @@ 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); >> } >> >> @@ -946,6 +983,88 @@ 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 because 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; >> + } >> + >> + /* pb[].offset and pb[].len are not changed during dma mapping >> + * and so not reassign. >> + */ >> + packet->dma_range[i].dma = dma; >> + packet->dma_range[i].mapping_size = len; >> + pb[i].pfn = dma >> HV_HYP_PAGE_SHIFT; >> + } >> + >> + return 0; >> +} >> + >> static inline int netvsc_send_pkt( >> struct hv_device *device, >> struct hv_netvsc_packet *packet, >> @@ -986,14 +1105,24 @@ 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; >> + } > > Returning EAGAIN will let the upper network layer busy retry, > which may make things worse. > I suggest to return ENOSPC here like another place in this > function, which will just drop the packet, and let the network > protocol/app layer decide how to recover. >
Yes, agree. Will update in the next version. Thanks.
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