RE: [PATCH V8 0/9] x86/Hyper-V: Add Hyper-V Isolation VM support(First part)

[Michael Kelley <mikelley@microsoft.com>]

From: Tianyu Lan <ltykernel@gmail.com> Sent: Thursday, October 21, 2021 8:41 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.
> 
> 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.
> 
> 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.
> 
> This patchset is rebased on the commit d9abdee of Linux mainline tree
> and plus clean up patch from Borislav
> Petkov
> 
> Change since v7
> 	- Rework sev_es_ghcb_hv_call() and export it for Hyper-V
> 	  according to suggestion from Borislav Petkov.
> 
> Change since v6
> 	- Add hv_set_mem_host_visibility() when CONFIG_HYPERV is no.
> 	  Fix compile error.
> 	- Add comment to describe __set_memory_enc_pgtable().
> 	- Split SEV change into patch "Expose __sev_es_ghcb_hv_call()
> 	  to call ghcb hv call out of sev code"
>  	- Add comment about calling memunmap() in the non-snp IVM.
> 
> Change since v5
> 	- Replace HVPFN_UP() with PFN_UP() in the __vmbus_establish_gpadl()
> 	- Remove unused variable gpadl in the __vmbus_open() and vmbus_close_
> 	  internal()
> 	- Clean gpadl_handle in the vmbus_teardown_gpadl().
> 	- Adjust change layout in the asm/mshyperv.h to make
> 	  hv_is_synic_reg(), hv_get_register() and hv_set_register()
> 	  ahead of the #include of asm-generic/mshyperv.h
> 	- Change vmbus_connection.monitor_pages_pa type from unsigned
> 	  long to phys_addr_t
> 
> Change since v4:
> 	- Hide hv_mark_gpa_visibility() and set memory visibility via
> 	  set_memory_encrypted/decrypted()
> 	- Change gpadl handle in netvsc and uio driver from u32 to
> 	  struct vmbus_gpadl.
> 	- Change vmbus_establish_gpadl()'s gpadl_handle parameter
> 	  to vmbus_gpadl data structure.
> 	- Remove hv_get_simp(), hv_get_siefp()  hv_get_synint_*()
> 	  helper function. Move the logic into hv_get/set_register().
> 	- Use scsi_dma_map/unmap() instead of dma_map/unmap_sg() in storvsc driver.
> 	- Allocate rx/tx ring buffer via alloc_pages() in Isolation VM
> 
> Change since V3:
> 	- Initalize GHCB page in the cpu init callbac.
> 	- Change vmbus_teardown_gpadl() parameter in order to
> 	  mask the memory back to non-visible to host.
> 	- Merge hv_ringbuffer_post_init() into hv_ringbuffer_init().
> 	- Keep Hyper-V bounce buffer size as same as AMD SEV VM
> 	- Use dma_map_sg() instead of dm_map_page() in the storvsc driver.
> 
> 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 (9):
>   x86/hyperv: Initialize GHCB page in Isolation VM
>   x86/hyperv: Initialize shared memory boundary in the Isolation VM.
>   x86/hyperv: Add new hvcall guest address host visibility  support
>   Drivers: hv: vmbus: Mark vmbus ring buffer visible to host in
>     Isolation VM
>   x86/sev-es: Expose sev_es_ghcb_hv_call() to call ghcb hv call out of
>     sev code
>   x86/hyperv: Add Write/Read MSR registers via ghcb page
>   x86/hyperv: Add ghcb hvcall support for SNP VM
>   Drivers: hv: vmbus: Add SNP support for VMbus channel initiate
>     message
>   Drivers: hv : vmbus: Initialize VMbus ring buffer for Isolation VM
> 
>  arch/x86/hyperv/Makefile           |   2 +-
>  arch/x86/hyperv/hv_init.c          |  78 ++++++--
>  arch/x86/hyperv/ivm.c              | 286 +++++++++++++++++++++++++++++
>  arch/x86/include/asm/hyperv-tlfs.h |  17 ++
>  arch/x86/include/asm/mshyperv.h    |  64 +++++--
>  arch/x86/include/asm/sev.h         |  12 ++
>  arch/x86/kernel/cpu/mshyperv.c     |   5 +
>  arch/x86/kernel/sev-shared.c       |  26 ++-
>  arch/x86/kernel/sev.c              |  13 +-
>  arch/x86/mm/pat/set_memory.c       |  23 ++-
>  drivers/hv/Kconfig                 |   1 +
>  drivers/hv/channel.c               |  72 +++++---
>  drivers/hv/connection.c            | 101 +++++++++-
>  drivers/hv/hv.c                    |  82 +++++++--
>  drivers/hv/hv_common.c             |  12 ++
>  drivers/hv/hyperv_vmbus.h          |   2 +
>  drivers/hv/ring_buffer.c           |  55 ++++--
>  drivers/net/hyperv/hyperv_net.h    |   5 +-
>  drivers/net/hyperv/netvsc.c        |  15 +-
>  drivers/uio/uio_hv_generic.c       |  18 +-
>  include/asm-generic/hyperv-tlfs.h  |   1 +
>  include/asm-generic/mshyperv.h     |  20 +-
>  include/linux/hyperv.h             |  12 +-
>  23 files changed, 783 insertions(+), 139 deletions(-)
>  create mode 100644 arch/x86/hyperv/ivm.c
> 
> --
> 2.25.1

For the entire series, modulo a minor missing argument error in a
declaration in Patch 5 that I noted separately,

Reviewed-by: Michael Kelley <mikelley@microsoft.com>