[RFC,V3,00/11] x86/Hyper-V: Add Hyper-V Isolation VM support

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:
       - 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 (11):
  x86/HV: Initialize GHCB page in Isolation VM
  x86/HV: Initialize shared memory boundary in the Isolation VM.
  x86/Hyper-V: Add new hvcall guest address host visibility support
  HV: Add Write/Read MSR registers via ghcb
  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
  swiotlb: Add bounce buffer remap address setting function
  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          |  70 +++++--
 arch/x86/hyperv/ivm.c              | 300 +++++++++++++++++++++++++++++
 arch/x86/include/asm/hyperv-tlfs.h |  24 +++
 arch/x86/include/asm/mshyperv.h    |  85 +++++++-
 arch/x86/kernel/cpu/mshyperv.c     |   5 +
 arch/x86/mm/pat/set_memory.c       |  10 +-
 arch/x86/xen/pci-swiotlb-xen.c     |   3 +-
 drivers/hv/Kconfig                 |   1 +
 drivers/hv/channel.c               |  48 ++++-
 drivers/hv/connection.c            |  68 ++++++-
 drivers/hv/hv.c                    | 122 ++++++++----
 drivers/hv/hyperv_vmbus.h          |   3 +
 drivers/hv/ring_buffer.c           |  84 ++++++--
 drivers/hv/vmbus_drv.c             |   3 +
 drivers/iommu/hyperv-iommu.c       |  81 ++++++++
 drivers/net/hyperv/hyperv_net.h    |   6 +
 drivers/net/hyperv/netvsc.c        | 125 +++++++++++-
 drivers/net/hyperv/rndis_filter.c  |   3 +
 drivers/scsi/storvsc_drv.c         |  63 +++++-
 include/asm-generic/hyperv-tlfs.h  |   1 +
 include/asm-generic/mshyperv.h     |  18 +-
 include/linux/hyperv.h             |  16 ++
 include/linux/swiotlb.h            |   5 +
 kernel/dma/swiotlb.c               |  14 +-
 25 files changed, 1062 insertions(+), 98 deletions(-)
 create mode 100644 arch/x86/hyperv/ivm.c

Hi Borislav:
	Thanks for your review.

On 5/31/2021 2:25 AM, Borislav Petkov wrote:
> On Sun, May 30, 2021 at 11:06:20AM -0400, Tianyu Lan wrote:

>> diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c

>> index 156cd235659f..a82975600107 100644

>> --- a/arch/x86/mm/pat/set_memory.c

>> +++ b/arch/x86/mm/pat/set_memory.c

>> @@ -29,6 +29,8 @@

>>   #include <asm/proto.h>

>>   #include <asm/memtype.h>

>>   #include <asm/set_memory.h>

>> +#include <asm/hyperv-tlfs.h>

>> +#include <asm/mshyperv.h>

>>   

>>   #include "../mm_internal.h"

>>   

>> @@ -1986,8 +1988,14 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)

>>   	int ret;

>>   

>>   	/* Nothing to do if memory encryption is not active */

>> -	if (!mem_encrypt_active())

>> +	if (hv_is_isolation_supported()) {

>> +		return hv_set_mem_host_visibility((void *)addr,

>> +				numpages * HV_HYP_PAGE_SIZE,

>> +				enc ? VMBUS_PAGE_NOT_VISIBLE

>> +				: VMBUS_PAGE_VISIBLE_READ_WRITE);

> 

> Put all this gunk in a hv-specific function somewhere in hv-land which

> you only call from here. This way you probably won't even need to export

> hv_set_mem_host_visibility() and so on...

> 


Good idea. Will update. Thanks.