<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/x86/kernel/cpu/mshyperv.c, branch v6.0</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'hyperv-next-signed-20220528' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux</title>
<updated>2022-05-28T18:39:01+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-05-28T18:39:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f56dbdda4322d33d485f3d30f3aabba71de9098c'/>
<id>f56dbdda4322d33d485f3d30f3aabba71de9098c</id>
<content type='text'>
Pull hyperv updates from Wei Liu:

 - Harden hv_sock driver (Andrea Parri)

 - Harden Hyper-V PCI driver (Andrea Parri)

 - Fix multi-MSI for Hyper-V PCI driver (Jeffrey Hugo)

 - Fix Hyper-V PCI to reduce boot time (Dexuan Cui)

 - Remove code for long EOL'ed Hyper-V versions (Michael Kelley, Saurabh
   Sengar)

 - Fix balloon driver error handling (Shradha Gupta)

 - Fix a typo in vmbus driver (Julia Lawall)

 - Ignore vmbus IMC device (Michael Kelley)

 - Add a new error message to Hyper-V DRM driver (Saurabh Sengar)

* tag 'hyperv-next-signed-20220528' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (28 commits)
  hv_balloon: Fix balloon_probe() and balloon_remove() error handling
  scsi: storvsc: Removing Pre Win8 related logic
  Drivers: hv: vmbus: fix typo in comment
  PCI: hv: Fix synchronization between channel callback and hv_pci_bus_exit()
  PCI: hv: Add validation for untrusted Hyper-V values
  PCI: hv: Fix interrupt mapping for multi-MSI
  PCI: hv: Reuse existing IRTE allocation in compose_msi_msg()
  drm/hyperv: Remove support for Hyper-V 2008 and 2008R2/Win7
  video: hyperv_fb: Remove support for Hyper-V 2008 and 2008R2/Win7
  scsi: storvsc: Remove support for Hyper-V 2008 and 2008R2/Win7
  Drivers: hv: vmbus: Remove support for Hyper-V 2008 and Hyper-V 2008R2/Win7
  x86/hyperv: Disable hardlockup detector by default in Hyper-V guests
  drm/hyperv: Add error message for fb size greater than allocated
  PCI: hv: Do not set PCI_COMMAND_MEMORY to reduce VM boot time
  PCI: hv: Fix hv_arch_irq_unmask() for multi-MSI
  Drivers: hv: vmbus: Refactor the ring-buffer iterator functions
  Drivers: hv: vmbus: Accept hv_sock offers in isolated guests
  hv_sock: Add validation for untrusted Hyper-V values
  hv_sock: Copy packets sent by Hyper-V out of the ring buffer
  hv_sock: Check hv_pkt_iter_first_raw()'s return value
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull hyperv updates from Wei Liu:

 - Harden hv_sock driver (Andrea Parri)

 - Harden Hyper-V PCI driver (Andrea Parri)

 - Fix multi-MSI for Hyper-V PCI driver (Jeffrey Hugo)

 - Fix Hyper-V PCI to reduce boot time (Dexuan Cui)

 - Remove code for long EOL'ed Hyper-V versions (Michael Kelley, Saurabh
   Sengar)

 - Fix balloon driver error handling (Shradha Gupta)

 - Fix a typo in vmbus driver (Julia Lawall)

 - Ignore vmbus IMC device (Michael Kelley)

 - Add a new error message to Hyper-V DRM driver (Saurabh Sengar)

* tag 'hyperv-next-signed-20220528' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (28 commits)
  hv_balloon: Fix balloon_probe() and balloon_remove() error handling
  scsi: storvsc: Removing Pre Win8 related logic
  Drivers: hv: vmbus: fix typo in comment
  PCI: hv: Fix synchronization between channel callback and hv_pci_bus_exit()
  PCI: hv: Add validation for untrusted Hyper-V values
  PCI: hv: Fix interrupt mapping for multi-MSI
  PCI: hv: Reuse existing IRTE allocation in compose_msi_msg()
  drm/hyperv: Remove support for Hyper-V 2008 and 2008R2/Win7
  video: hyperv_fb: Remove support for Hyper-V 2008 and 2008R2/Win7
  scsi: storvsc: Remove support for Hyper-V 2008 and 2008R2/Win7
  Drivers: hv: vmbus: Remove support for Hyper-V 2008 and Hyper-V 2008R2/Win7
  x86/hyperv: Disable hardlockup detector by default in Hyper-V guests
  drm/hyperv: Add error message for fb size greater than allocated
  PCI: hv: Do not set PCI_COMMAND_MEMORY to reduce VM boot time
  PCI: hv: Fix hv_arch_irq_unmask() for multi-MSI
  Drivers: hv: vmbus: Refactor the ring-buffer iterator functions
  Drivers: hv: vmbus: Accept hv_sock offers in isolated guests
  hv_sock: Add validation for untrusted Hyper-V values
  hv_sock: Copy packets sent by Hyper-V out of the ring buffer
  hv_sock: Check hv_pkt_iter_first_raw()'s return value
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/hyperv: Disable hardlockup detector by default in Hyper-V guests</title>
<updated>2022-05-11T14:36:46+00:00</updated>
<author>
<name>Michael Kelley</name>
<email>mikelley@microsoft.com</email>
</author>
<published>2022-05-09T15:44:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f1f8288d19d03af9d03db219c23d07a6e8ecd51b'/>
<id>f1f8288d19d03af9d03db219c23d07a6e8ecd51b</id>
<content type='text'>
In newer versions of Hyper-V, the x86/x64 PMU can be virtualized
into guest VMs by explicitly enabling it. Linux kernels are typically
built to automatically enable the hardlockup detector if the PMU is
found. To prevent the possibility of false positives due to the
vagaries of VM scheduling, disable the PMU-based hardlockup detector
by default in a VM on Hyper-V.  The hardlockup detector can still be
enabled by overriding the default with the nmi_watchdog=1 option on
the kernel boot line or via sysctl at runtime.

This change mimics the approach taken with KVM guests in
commit 692297d8f968 ("watchdog: introduce the hardlockup_detector_disable()
function").

Linux on ARM64 does not provide a PMU-based hardlockup detector, so
there's no corresponding disable in the Hyper-V init code on ARM64.

Signed-off-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Link: https://lore.kernel.org/r/1652111063-6535-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In newer versions of Hyper-V, the x86/x64 PMU can be virtualized
into guest VMs by explicitly enabling it. Linux kernels are typically
built to automatically enable the hardlockup detector if the PMU is
found. To prevent the possibility of false positives due to the
vagaries of VM scheduling, disable the PMU-based hardlockup detector
by default in a VM on Hyper-V.  The hardlockup detector can still be
enabled by overriding the default with the nmi_watchdog=1 option on
the kernel boot line or via sysctl at runtime.

This change mimics the approach taken with KVM guests in
commit 692297d8f968 ("watchdog: introduce the hardlockup_detector_disable()
function").

Linux on ARM64 does not provide a PMU-based hardlockup detector, so
there's no corresponding disable in the Hyper-V init code on ARM64.

Signed-off-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Link: https://lore.kernel.org/r/1652111063-6535-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86: centralize setting SWIOTLB_FORCE when guest memory encryption is enabled</title>
<updated>2022-04-18T05:21:10+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2022-03-29T15:25:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a3e230926708125205ffd06d3dc2175a8263ae7e'/>
<id>a3e230926708125205ffd06d3dc2175a8263ae7e</id>
<content type='text'>
Move enabling SWIOTLB_FORCE for guest memory encryption into common code.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt;
Tested-by: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Move enabling SWIOTLB_FORCE for guest memory encryption into common code.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt;
Tested-by: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'hyperv-next-signed-20220322' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux</title>
<updated>2022-03-24T19:30:37+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-24T19:30:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=66711cfea642a162bc99abdefe1645b26dbd778f'/>
<id>66711cfea642a162bc99abdefe1645b26dbd778f</id>
<content type='text'>
Pull hyperv updates from Wei Liu:
 "Minor patches from various people"

* tag 'hyperv-next-signed-20220322' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: Output host build info as normal Windows version number
  hv_balloon: rate-limit "Unhandled message" warning
  drivers: hv: log when enabling crash_kexec_post_notifiers
  hv_utils: Add comment about max VMbus packet size in VSS driver
  Drivers: hv: Compare cpumasks and not their weights in init_vp_index()
  Drivers: hv: Rename 'alloced' to 'allocated'
  Drivers: hv: vmbus: Use struct_size() helper in kmalloc()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull hyperv updates from Wei Liu:
 "Minor patches from various people"

* tag 'hyperv-next-signed-20220322' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: Output host build info as normal Windows version number
  hv_balloon: rate-limit "Unhandled message" warning
  drivers: hv: log when enabling crash_kexec_post_notifiers
  hv_utils: Add comment about max VMbus packet size in VSS driver
  Drivers: hv: Compare cpumasks and not their weights in init_vp_index()
  Drivers: hv: Rename 'alloced' to 'allocated'
  Drivers: hv: vmbus: Use struct_size() helper in kmalloc()
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/hyperv: Output host build info as normal Windows version number</title>
<updated>2022-03-08T20:44:50+00:00</updated>
<author>
<name>Michael Kelley</name>
<email>mikelley@microsoft.com</email>
</author>
<published>2022-03-08T19:22:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=eeda29db98f429a3b6473117e6ce1c213ab614f2'/>
<id>eeda29db98f429a3b6473117e6ce1c213ab614f2</id>
<content type='text'>
Hyper-V provides host version number information that is output in
text form by a Linux guest when it boots. For whatever reason, the
formatting has historically been non-standard. Change it to output
in normal Windows version format for better readability.

Similar code for ARM64 guests already outputs in normal Windows
version format.

Signed-off-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Link: https://lore.kernel.org/r/1646767364-2234-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Hyper-V provides host version number information that is output in
text form by a Linux guest when it boots. For whatever reason, the
formatting has historically been non-standard. Change it to output
in normal Windows version format for better readability.

Similar code for ARM64 guests already outputs in normal Windows
version format.

Signed-off-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Link: https://lore.kernel.org/r/1646767364-2234-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/coco: Explicitly declare type of confidential computing platform</title>
<updated>2022-02-23T18:14:16+00:00</updated>
<author>
<name>Kirill A. Shutemov</name>
<email>kirill.shutemov@linux.intel.com</email>
</author>
<published>2022-02-22T18:57:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=655a0fa34b4f7ac6e2b1406fab15e52a7b6accb1'/>
<id>655a0fa34b4f7ac6e2b1406fab15e52a7b6accb1</id>
<content type='text'>
The kernel derives the confidential computing platform
type it is running as from sme_me_mask on AMD or by using
hv_is_isolation_supported() on HyperV isolation VMs. This detection
process will be more complicated as more platforms get added.

Declare a confidential computing vendor variable explicitly and set it
via cc_set_vendor() on the respective platform.

  [ bp: Massage commit message, fixup HyperV check. ]

Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Reviewed-by: Tom Lendacky &lt;thomas.lendacky@amd.com&gt;
Link: https://lore.kernel.org/r/20220222185740.26228-4-kirill.shutemov@linux.intel.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The kernel derives the confidential computing platform
type it is running as from sme_me_mask on AMD or by using
hv_is_isolation_supported() on HyperV isolation VMs. This detection
process will be more complicated as more platforms get added.

Declare a confidential computing vendor variable explicitly and set it
via cc_set_vendor() on the respective platform.

  [ bp: Massage commit message, fixup HyperV check. ]

Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Reviewed-by: Tom Lendacky &lt;thomas.lendacky@amd.com&gt;
Link: https://lore.kernel.org/r/20220222185740.26228-4-kirill.shutemov@linux.intel.com
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'hyperv-next-signed-20220114' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux</title>
<updated>2022-01-16T13:53:00+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-01-16T13:53:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cb3f09f9afe5286c0aed7a1c5cc71495de166efb'/>
<id>cb3f09f9afe5286c0aed7a1c5cc71495de166efb</id>
<content type='text'>
Pull hyperv updates from Wei Liu:

 - More patches for Hyper-V isolation VM support (Tianyu Lan)

 - Bug fixes and clean-up patches from various people

* tag 'hyperv-next-signed-20220114' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  scsi: storvsc: Fix storvsc_queuecommand() memory leak
  x86/hyperv: Properly deal with empty cpumasks in hyperv_flush_tlb_multi()
  Drivers: hv: vmbus: Initialize request offers message for Isolation VM
  scsi: storvsc: Fix unsigned comparison to zero
  swiotlb: Add CONFIG_HAS_IOMEM check around swiotlb_mem_remap()
  x86/hyperv: Fix definition of hv_ghcb_pg variable
  Drivers: hv: Fix definition of hypercall input &amp; output arg variables
  net: netvsc: Add Isolation VM support for netvsc driver
  scsi: storvsc: Add Isolation VM support for storvsc driver
  hyper-v: Enable swiotlb bounce buffer for Isolation VM
  x86/hyper-v: Add hyperv Isolation VM check in the cc_platform_has()
  swiotlb: Add swiotlb bounce buffer remap function for HV IVM
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull hyperv updates from Wei Liu:

 - More patches for Hyper-V isolation VM support (Tianyu Lan)

 - Bug fixes and clean-up patches from various people

* tag 'hyperv-next-signed-20220114' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  scsi: storvsc: Fix storvsc_queuecommand() memory leak
  x86/hyperv: Properly deal with empty cpumasks in hyperv_flush_tlb_multi()
  Drivers: hv: vmbus: Initialize request offers message for Isolation VM
  scsi: storvsc: Fix unsigned comparison to zero
  swiotlb: Add CONFIG_HAS_IOMEM check around swiotlb_mem_remap()
  x86/hyperv: Fix definition of hv_ghcb_pg variable
  Drivers: hv: Fix definition of hypercall input &amp; output arg variables
  net: netvsc: Add Isolation VM support for netvsc driver
  scsi: storvsc: Add Isolation VM support for storvsc driver
  hyper-v: Enable swiotlb bounce buffer for Isolation VM
  x86/hyper-v: Add hyperv Isolation VM check in the cc_platform_has()
  swiotlb: Add swiotlb bounce buffer remap function for HV IVM
</pre>
</div>
</content>
</entry>
<entry>
<title>random: remove unused irq_flags argument from add_interrupt_randomness()</title>
<updated>2022-01-06T23:25:25+00:00</updated>
<author>
<name>Sebastian Andrzej Siewior</name>
<email>bigeasy@linutronix.de</email>
</author>
<published>2021-12-07T12:17:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=703f7066f40599c290babdb79dd61319264987e9'/>
<id>703f7066f40599c290babdb79dd61319264987e9</id>
<content type='text'>
Since commit
   ee3e00e9e7101 ("random: use registers from interrupted code for CPU's w/o a cycle counter")

the irq_flags argument is no longer used.

Remove unused irq_flags.

Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Dexuan Cui &lt;decui@microsoft.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Haiyang Zhang &lt;haiyangz@microsoft.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: K. Y. Srinivasan &lt;kys@microsoft.com&gt;
Cc: Stephen Hemminger &lt;sthemmin@microsoft.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Wei Liu &lt;wei.liu@kernel.org&gt;
Cc: linux-hyperv@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Acked-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since commit
   ee3e00e9e7101 ("random: use registers from interrupted code for CPU's w/o a cycle counter")

the irq_flags argument is no longer used.

Remove unused irq_flags.

Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Dexuan Cui &lt;decui@microsoft.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Haiyang Zhang &lt;haiyangz@microsoft.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: K. Y. Srinivasan &lt;kys@microsoft.com&gt;
Cc: Stephen Hemminger &lt;sthemmin@microsoft.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Wei Liu &lt;wei.liu@kernel.org&gt;
Cc: linux-hyperv@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Acked-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>hyper-v: Enable swiotlb bounce buffer for Isolation VM</title>
<updated>2021-12-20T18:01:09+00:00</updated>
<author>
<name>Tianyu Lan</name>
<email>Tianyu.Lan@microsoft.com</email>
</author>
<published>2021-12-13T07:14:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=062a5c4260cdb734a4727230c58e38accf413315'/>
<id>062a5c4260cdb734a4727230c58e38accf413315</id>
<content type='text'>
hyperv Isolation VM requires bounce buffer support to copy
data from/to encrypted memory and so enable swiotlb force
mode to use swiotlb bounce buffer for DMA transaction.

In Isolation VM with AMD SEV, the bounce buffer needs to be
accessed via extra address space which is above shared_gpa_boundary
(E.G 39 bit address line) reported by Hyper-V CPUID ISOLATION_CONFIG.
The access physical address will be original physical address +
shared_gpa_boundary. The shared_gpa_boundary in the AMD SEV SNP
spec is called virtual top of memory(vTOM). Memory addresses below
vTOM are automatically treated as private while memory above
vTOM is treated as shared.

Swiotlb bounce buffer code calls set_memory_decrypted()
to mark bounce buffer visible to host and map it in extra
address space via memremap. Populate the shared_gpa_boundary
(vTOM) via swiotlb_unencrypted_base variable.

The map function memremap() can't work in the early place
(e.g ms_hyperv_init_platform()) and so call swiotlb_update_mem_
attributes() in the hyperv_init().

Signed-off-by: Tianyu Lan &lt;Tianyu.Lan@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Link: https://lore.kernel.org/r/20211213071407.314309-4-ltykernel@gmail.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
hyperv Isolation VM requires bounce buffer support to copy
data from/to encrypted memory and so enable swiotlb force
mode to use swiotlb bounce buffer for DMA transaction.

In Isolation VM with AMD SEV, the bounce buffer needs to be
accessed via extra address space which is above shared_gpa_boundary
(E.G 39 bit address line) reported by Hyper-V CPUID ISOLATION_CONFIG.
The access physical address will be original physical address +
shared_gpa_boundary. The shared_gpa_boundary in the AMD SEV SNP
spec is called virtual top of memory(vTOM). Memory addresses below
vTOM are automatically treated as private while memory above
vTOM is treated as shared.

Swiotlb bounce buffer code calls set_memory_decrypted()
to mark bounce buffer visible to host and map it in extra
address space via memremap. Populate the shared_gpa_boundary
(vTOM) via swiotlb_unencrypted_base variable.

The map function memremap() can't work in the early place
(e.g ms_hyperv_init_platform()) and so call swiotlb_update_mem_
attributes() in the hyperv_init().

Signed-off-by: Tianyu Lan &lt;Tianyu.Lan@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Link: https://lore.kernel.org/r/20211213071407.314309-4-ltykernel@gmail.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/hyperv: Move required MSRs check to initial platform probing</title>
<updated>2021-11-15T12:37:08+00:00</updated>
<author>
<name>Sean Christopherson</name>
<email>seanjc@google.com</email>
</author>
<published>2021-11-04T18:22:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f3e613e72f66226b3bea1046c1b864f67a3000a4'/>
<id>f3e613e72f66226b3bea1046c1b864f67a3000a4</id>
<content type='text'>
Explicitly check for MSR_HYPERCALL and MSR_VP_INDEX support when probing
for running as a Hyper-V guest instead of waiting until hyperv_init() to
detect the bogus configuration.  Add messages to give the admin a heads
up that they are likely running on a broken virtual machine setup.

At best, silently disabling Hyper-V is confusing and difficult to debug,
e.g. the kernel _says_ it's using all these fancy Hyper-V features, but
always falls back to the native versions.  At worst, the half baked setup
will crash/hang the kernel.

Reviewed-by: Vitaly Kuznetsov &lt;vkuznets@redhat.com&gt;
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
Link: https://lore.kernel.org/r/20211104182239.1302956-3-seanjc@google.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Explicitly check for MSR_HYPERCALL and MSR_VP_INDEX support when probing
for running as a Hyper-V guest instead of waiting until hyperv_init() to
detect the bogus configuration.  Add messages to give the admin a heads
up that they are likely running on a broken virtual machine setup.

At best, silently disabling Hyper-V is confusing and difficult to debug,
e.g. the kernel _says_ it's using all these fancy Hyper-V features, but
always falls back to the native versions.  At worst, the half baked setup
will crash/hang the kernel.

Reviewed-by: Vitaly Kuznetsov &lt;vkuznets@redhat.com&gt;
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
Link: https://lore.kernel.org/r/20211104182239.1302956-3-seanjc@google.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
