| Message ID | 20210809175620.720923-1-ltykernel@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | x86/Hyper-V: Add Hyper-V Isolation VM support | expand |
From: Tianyu Lan <ltykernel@gmail.com> Sent: Monday, August 9, 2021 10:56 AM > > Hyper-V provides two kinds of Isolation VMs. VBS(Virtualization-based > security) and AMD SEV-SNP unenlightened Isolation VMs. This patchset > is to add support for these Isolation VM support in Linux. > A general comment about this series: I have not seen any statements made about whether either type of Isolated VM is supported for 32-bit Linux guests. arch/x86/Kconfig has CONFIG_AMD_MEM_ENCRYPT as 64-bit only, so evidently SEV-SNP Isolated VMs would be 64-bit only. But I don't know if VBS VMs are any different. I didn't track down what happens if a 32-bit Linux is booted in a VM that supports SEV-SNP. Presumably some kind of message is output that no encryption is being done. But at a slightly higher level, the Hyper-V initialization path should probably also check for 32-bit and output a clear message that no isolation is being provided. At that point, I don't know if it is possible to continue in non-isolated mode or whether the only choice is to panic. Continuing in non-isolated mode might be a bad idea anyway since presumably the user has explicitly requested an Isolated VM. Related, I noticed usage of "unsigned long" for holding physical addresses, which works when running 64-bit, but not when running 32-bit. But even if Isolated VMs are always 64-bit, it would be still be better to clean this up and use phys_addr_t instead. Unfortunately, more generic functions like set_memory_encrypted() and set_memory_decrypted() have physical address arguments that are of type unsigned long. Michael
From: Tianyu Lan <Tianyu.Lan@microsoft.com> Hyper-V provides two kinds of Isolation VMs. VBS(Virtualization-based security) and AMD SEV-SNP unenlightened Isolation VMs. This patchset is to add support for these Isolation VM support in Linux. The memory of these vms are encrypted and host can't access guest memory directly. Hyper-V provides new host visibility hvcall and the guest needs to call new hvcall to mark memory visible to host before sharing memory with host. For security, all network/storage stack memory should not be shared with host and so there is bounce buffer requests. Vmbus channel ring buffer already plays bounce buffer role because all data from/to host needs to copy from/to between the ring buffer and IO stack memory. So mark vmbus channel ring buffer visible. There are two exceptions - packets sent by vmbus_sendpacket_ pagebuffer() and vmbus_sendpacket_mpb_desc(). These packets contains IO stack memory address and host will access these memory. So add allocation bounce buffer support in vmbus for these packets. For SNP isolation VM, guest needs to access the shared memory via extra address space which is specified by Hyper-V CPUID HYPERV_CPUID_ ISOLATION_CONFIG. The access physical address of the shared memory should be bounce buffer memory GPA plus with shared_gpa_boundary reported by CPUID. Change since V2: - Drop x86_set_memory_enc static call and use platform check in the __set_memory_enc_dec() to run platform callback of set memory encrypted or decrypted. Change since V1: - Introduce x86_set_memory_enc static call and so platforms can override __set_memory_enc_dec() with their implementation - Introduce sev_es_ghcb_hv_call_simple() and share code between SEV and Hyper-V code. - Not remap monitor pages in the non-SNP isolation VM - Make swiotlb_init_io_tlb_mem() return error code and return error when dma_map_decrypted() fails. Change since RFC V4: - Introduce dma map decrypted function to remap bounce buffer and provide dma map decrypted ops for platform to hook callback. - Split swiotlb and dma map decrypted change into two patches - Replace vstart with vaddr in swiotlb changes. Change since RFC v3: - Add interface set_memory_decrypted_map() to decrypt memory and map bounce buffer in extra address space - Remove swiotlb remap function and store the remap address returned by set_memory_decrypted_map() in swiotlb mem data structure. - Introduce hv_set_mem_enc() to make code more readable in the __set_memory_enc_dec(). Change since RFC v2: - Remove not UIO driver in Isolation VM patch - Use vmap_pfn() to replace ioremap_page_range function in order to avoid exposing symbol ioremap_page_range() and ioremap_page_range() - Call hv set mem host visibility hvcall in set_memory_encrypted/decrypted() - Enable swiotlb force mode instead of adding Hyper-V dma map/unmap hook - Fix code style Tianyu Lan (13): x86/HV: Initialize GHCB page in Isolation VM x86/HV: Initialize shared memory boundary in the Isolation VM. x86/HV: Add new hvcall guest address host visibility support HV: Mark vmbus ring buffer visible to host in Isolation VM HV: Add Write/Read MSR registers via ghcb page HV: Add ghcb hvcall support for SNP VM HV/Vmbus: Add SNP support for VMbus channel initiate message HV/Vmbus: Initialize VMbus ring buffer for Isolation VM DMA: Add dma_map_decrypted/dma_unmap_encrypted() function x86/Swiotlb: Add Swiotlb bounce buffer remap function for HV IVM HV/IOMMU: Enable swiotlb bounce buffer for Isolation VM HV/Netvsc: Add Isolation VM support for netvsc driver HV/Storvsc: Add Isolation VM support for storvsc driver arch/x86/hyperv/Makefile | 2 +- arch/x86/hyperv/hv_init.c | 75 ++++++-- arch/x86/hyperv/ivm.c | 295 +++++++++++++++++++++++++++++ arch/x86/include/asm/hyperv-tlfs.h | 20 ++ arch/x86/include/asm/mshyperv.h | 87 ++++++++- arch/x86/include/asm/sev.h | 3 + arch/x86/kernel/cpu/mshyperv.c | 5 + arch/x86/kernel/sev-shared.c | 63 +++--- arch/x86/mm/pat/set_memory.c | 19 +- arch/x86/xen/pci-swiotlb-xen.c | 3 +- drivers/hv/Kconfig | 1 + drivers/hv/channel.c | 54 +++++- drivers/hv/connection.c | 71 ++++++- drivers/hv/hv.c | 129 +++++++++---- drivers/hv/hyperv_vmbus.h | 3 + drivers/hv/ring_buffer.c | 84 ++++++-- drivers/hv/vmbus_drv.c | 3 + drivers/iommu/hyperv-iommu.c | 65 +++++++ drivers/net/hyperv/hyperv_net.h | 6 + drivers/net/hyperv/netvsc.c | 144 +++++++++++++- drivers/net/hyperv/rndis_filter.c | 2 + drivers/scsi/storvsc_drv.c | 68 ++++++- include/asm-generic/hyperv-tlfs.h | 1 + include/asm-generic/mshyperv.h | 54 +++++- include/linux/dma-map-ops.h | 9 + include/linux/hyperv.h | 17 ++ include/linux/swiotlb.h | 4 + kernel/dma/mapping.c | 22 +++ kernel/dma/swiotlb.c | 32 +++- 29 files changed, 1212 insertions(+), 129 deletions(-) create mode 100644 arch/x86/hyperv/ivm.c