<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/drivers/hv, branch v6.6.39</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v6.6.39</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v6.6.39'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2024-05-17T10:02:17+00:00</updated>
<entry>
<title>Drivers: hv: vmbus: Don't free ring buffers that couldn't be re-encrypted</title>
<updated>2024-05-17T10:02:17+00:00</updated>
<author>
<name>Michael Kelley</name>
<email>mhklinux@outlook.com</email>
</author>
<published>2024-03-11T16:15:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=82f9e213b124a7d2bb5b16ea35d570260ef467e0'/>
<id>urn:sha1:82f9e213b124a7d2bb5b16ea35d570260ef467e0</id>
<content type='text'>
[ Upstream commit 30d18df6567be09c1433e81993e35e3da573ac48 ]

In CoCo VMs it is possible for the untrusted host to cause
set_memory_encrypted() or set_memory_decrypted() to fail such that an
error is returned and the resulting memory is shared. Callers need to
take care to handle these errors to avoid returning decrypted (shared)
memory to the page allocator, which could lead to functional or security
issues.

The VMBus ring buffer code could free decrypted/shared pages if
set_memory_decrypted() fails. Check the decrypted field in the struct
vmbus_gpadl for the ring buffers to decide whether to free the memory.

Signed-off-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Reviewed-by: Kuppuswamy Sathyanarayanan &lt;sathyanarayanan.kuppuswamy@linux.intel.com&gt;
Acked-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20240311161558.1310-6-mhklinux@outlook.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;20240311161558.1310-6-mhklinux@outlook.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>Drivers: hv: vmbus: Track decrypted status in vmbus_gpadl</title>
<updated>2024-05-17T10:02:17+00:00</updated>
<author>
<name>Rick Edgecombe</name>
<email>rick.p.edgecombe@intel.com</email>
</author>
<published>2024-03-11T16:15:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8e62341f5c45b27519b7d193bcc32ada416ad9d8'/>
<id>urn:sha1:8e62341f5c45b27519b7d193bcc32ada416ad9d8</id>
<content type='text'>
[ Upstream commit 211f514ebf1ef5de37b1cf6df9d28a56cfd242ca ]

In CoCo VMs it is possible for the untrusted host to cause
set_memory_encrypted() or set_memory_decrypted() to fail such that an
error is returned and the resulting memory is shared. Callers need to
take care to handle these errors to avoid returning decrypted (shared)
memory to the page allocator, which could lead to functional or security
issues.

In order to make sure callers of vmbus_establish_gpadl() and
vmbus_teardown_gpadl() don't return decrypted/shared pages to
allocators, add a field in struct vmbus_gpadl to keep track of the
decryption status of the buffers. This will allow the callers to
know if they should free or leak the pages.

Signed-off-by: Rick Edgecombe &lt;rick.p.edgecombe@intel.com&gt;
Signed-off-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Reviewed-by: Kuppuswamy Sathyanarayanan &lt;sathyanarayanan.kuppuswamy@linux.intel.com&gt;
Acked-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20240311161558.1310-3-mhklinux@outlook.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;20240311161558.1310-3-mhklinux@outlook.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>Drivers: hv: vmbus: Leak pages if set_memory_encrypted() fails</title>
<updated>2024-05-17T10:02:17+00:00</updated>
<author>
<name>Rick Edgecombe</name>
<email>rick.p.edgecombe@intel.com</email>
</author>
<published>2024-03-11T16:15:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=6123a4e8e25bd40cf44db14694abac00e6b664e6'/>
<id>urn:sha1:6123a4e8e25bd40cf44db14694abac00e6b664e6</id>
<content type='text'>
[ Upstream commit 03f5a999adba062456c8c818a683beb1b498983a ]

In CoCo VMs it is possible for the untrusted host to cause
set_memory_encrypted() or set_memory_decrypted() to fail such that an
error is returned and the resulting memory is shared. Callers need to
take care to handle these errors to avoid returning decrypted (shared)
memory to the page allocator, which could lead to functional or security
issues.

VMBus code could free decrypted pages if set_memory_encrypted()/decrypted()
fails. Leak the pages if this happens.

Signed-off-by: Rick Edgecombe &lt;rick.p.edgecombe@intel.com&gt;
Signed-off-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Reviewed-by: Kuppuswamy Sathyanarayanan &lt;sathyanarayanan.kuppuswamy@linux.intel.com&gt;
Acked-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20240311161558.1310-2-mhklinux@outlook.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;20240311161558.1310-2-mhklinux@outlook.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>x86/hyperv: Use per cpu initial stack for vtl context</title>
<updated>2024-03-26T22:20:06+00:00</updated>
<author>
<name>Saurabh Sengar</name>
<email>ssengar@linux.microsoft.com</email>
</author>
<published>2024-03-03T08:01:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=3d6af30f177f8c3417437ca963992075f6c18bec'/>
<id>urn:sha1:3d6af30f177f8c3417437ca963992075f6c18bec</id>
<content type='text'>
[ Upstream commit 2b4b90e053a29057fb05ba81acce26bddce8d404 ]

Currently, the secondary CPUs in Hyper-V VTL context lack support for
parallel startup. Therefore, relying on the single initial_stack fetched
from the current task structure suffices for all vCPUs.

However, common initial_stack risks stack corruption when parallel startup
is enabled. In order to facilitate parallel startup, use the initial_stack
from the per CPU idle thread instead of the current task.

Fixes: 3be1bc2fe9d2 ("x86/hyperv: VTL support for Hyper-V")
Signed-off-by: Saurabh Sengar &lt;ssengar@linux.microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Link: https://lore.kernel.org/r/1709452896-13342-1-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;1709452896-13342-1-git-send-email-ssengar@linux.microsoft.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'hyperv-next-signed-20230902' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux</title>
<updated>2023-09-04T18:26:29+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-09-04T18:26:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=0b90c5637dfea8a08f87db5dd16000eb679013a3'/>
<id>urn:sha1:0b90c5637dfea8a08f87db5dd16000eb679013a3</id>
<content type='text'>
Pull hyperv updates from Wei Liu:

 - Support for SEV-SNP guests on Hyper-V (Tianyu Lan)

 - Support for TDX guests on Hyper-V (Dexuan Cui)

 - Use SBRM API in Hyper-V balloon driver (Mitchell Levy)

 - Avoid dereferencing ACPI root object handle in VMBus driver (Maciej
   Szmigiero)

 - A few misecllaneous fixes (Jiapeng Chong, Nathan Chancellor, Saurabh
   Sengar)

* tag 'hyperv-next-signed-20230902' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (24 commits)
  x86/hyperv: Remove duplicate include
  x86/hyperv: Move the code in ivm.c around to avoid unnecessary ifdef's
  x86/hyperv: Remove hv_isolation_type_en_snp
  x86/hyperv: Use TDX GHCI to access some MSRs in a TDX VM with the paravisor
  Drivers: hv: vmbus: Bring the post_msg_page back for TDX VMs with the paravisor
  x86/hyperv: Introduce a global variable hyperv_paravisor_present
  Drivers: hv: vmbus: Support &gt;64 VPs for a fully enlightened TDX/SNP VM
  x86/hyperv: Fix serial console interrupts for fully enlightened TDX guests
  Drivers: hv: vmbus: Support fully enlightened TDX guests
  x86/hyperv: Support hypercalls for fully enlightened TDX guests
  x86/hyperv: Add hv_isolation_type_tdx() to detect TDX guests
  x86/hyperv: Fix undefined reference to isolation_type_en_snp without CONFIG_HYPERV
  x86/hyperv: Add missing 'inline' to hv_snp_boot_ap() stub
  hv: hyperv.h: Replace one-element array with flexible-array member
  Drivers: hv: vmbus: Don't dereference ACPI root object handle
  x86/hyperv: Add hyperv-specific handling for VMMCALL under SEV-ES
  x86/hyperv: Add smp support for SEV-SNP guest
  clocksource: hyper-v: Mark hyperv tsc page unencrypted in sev-snp enlightened guest
  x86/hyperv: Use vmmcall to implement Hyper-V hypercall in sev-snp enlightened guest
  drivers: hv: Mark percpu hvcall input arg page unencrypted in SEV-SNP enlightened guest
  ...
</content>
</entry>
<entry>
<title>x86/hyperv: Remove hv_isolation_type_en_snp</title>
<updated>2023-08-25T00:04:57+00:00</updated>
<author>
<name>Dexuan Cui</name>
<email>decui@microsoft.com</email>
</author>
<published>2023-08-24T08:07:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=e3131f1c81448a87e08dffd21867312a5ce563d9'/>
<id>urn:sha1:e3131f1c81448a87e08dffd21867312a5ce563d9</id>
<content type='text'>
In ms_hyperv_init_platform(), do not distinguish between a SNP VM with
the paravisor and a SNP VM without the paravisor.

Replace hv_isolation_type_en_snp() with
!ms_hyperv.paravisor_present &amp;&amp; hv_isolation_type_snp().

The hv_isolation_type_en_snp() in drivers/hv/hv.c and
drivers/hv/hv_common.c can be changed to hv_isolation_type_snp() since
we know !ms_hyperv.paravisor_present is true there.

Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Reviewed-by: Tianyu Lan &lt;tiala@microsoft.com&gt;
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Link: https://lore.kernel.org/r/20230824080712.30327-10-decui@microsoft.com
</content>
</entry>
<entry>
<title>Drivers: hv: vmbus: Bring the post_msg_page back for TDX VMs with the paravisor</title>
<updated>2023-08-25T00:04:57+00:00</updated>
<author>
<name>Dexuan Cui</name>
<email>decui@microsoft.com</email>
</author>
<published>2023-08-24T08:07:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=23378295042a4bcaeec350733a4771678e7a1f3a'/>
<id>urn:sha1:23378295042a4bcaeec350733a4771678e7a1f3a</id>
<content type='text'>
The post_msg_page was removed in
commit 9a6b1a170ca8 ("Drivers: hv: vmbus: Remove the per-CPU post_msg_page")

However, it turns out that we need to bring it back, but only for a TDX VM
with the paravisor: in such a VM, the hyperv_pcpu_input_arg is not decrypted,
but the HVCALL_POST_MESSAGE in such a VM needs a decrypted page as the
hypercall input page: see the comments in hyperv_init() for a detailed
explanation.

Except for HVCALL_POST_MESSAGE and HVCALL_SIGNAL_EVENT, the other hypercalls
in a TDX VM with the paravisor still use hv_hypercall_pg and must use the
hyperv_pcpu_input_arg (which is encrypted in such a VM), when a hypercall
input page is used.

Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reviewed-by: Tianyu Lan &lt;tiala@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Link: https://lore.kernel.org/r/20230824080712.30327-8-decui@microsoft.com
</content>
</entry>
<entry>
<title>x86/hyperv: Introduce a global variable hyperv_paravisor_present</title>
<updated>2023-08-25T00:04:57+00:00</updated>
<author>
<name>Dexuan Cui</name>
<email>decui@microsoft.com</email>
</author>
<published>2023-08-24T08:07:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=d3a9d7e49d15316f68f4347f48adcd1665834980'/>
<id>urn:sha1:d3a9d7e49d15316f68f4347f48adcd1665834980</id>
<content type='text'>
The new variable hyperv_paravisor_present is set only when the VM
is a SNP/TDX VM with the paravisor running: see ms_hyperv_init_platform().

We introduce hyperv_paravisor_present because we can not use
ms_hyperv.paravisor_present in arch/x86/include/asm/mshyperv.h:

struct ms_hyperv_info is defined in include/asm-generic/mshyperv.h, which
is included at the end of arch/x86/include/asm/mshyperv.h, but at the
beginning of arch/x86/include/asm/mshyperv.h, we would already need to use
struct ms_hyperv_info in hv_do_hypercall().

We use hyperv_paravisor_present only in include/asm-generic/mshyperv.h,
and use ms_hyperv.paravisor_present elsewhere. In the future, we'll
introduce a hypercall function structure for different VM types, and
at boot time, the right function pointers would be written into the
structure so that runtime testing of TDX vs. SNP vs. normal will be
avoided and hyperv_paravisor_present will no longer be needed.

Call hv_vtom_init() when it's a VBS VM or when ms_hyperv.paravisor_present
is true, i.e. the VM is a SNP VM or TDX VM with the paravisor.

Enhance hv_vtom_init() for a TDX VM with the paravisor.

In hv_common_cpu_init(), don't decrypt the hyperv_pcpu_input_arg
for a TDX VM with the paravisor, just like we don't decrypt the page
for a SNP VM with the paravisor.

Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reviewed-by: Tianyu Lan &lt;tiala@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Link: https://lore.kernel.org/r/20230824080712.30327-7-decui@microsoft.com
</content>
</entry>
<entry>
<title>Drivers: hv: vmbus: Support &gt;64 VPs for a fully enlightened TDX/SNP VM</title>
<updated>2023-08-25T00:04:56+00:00</updated>
<author>
<name>Dexuan Cui</name>
<email>decui@microsoft.com</email>
</author>
<published>2023-08-24T08:07:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=cceb4e0810b61c7f5837c17e966b9b718dd62d22'/>
<id>urn:sha1:cceb4e0810b61c7f5837c17e966b9b718dd62d22</id>
<content type='text'>
Don't set *this_cpu_ptr(hyperv_pcpu_input_arg) before the function
set_memory_decrypted() returns, otherwise we run into this ticky issue:

For a fully enlightened TDX/SNP VM, in hv_common_cpu_init(),
*this_cpu_ptr(hyperv_pcpu_input_arg) is an encrypted page before
the set_memory_decrypted() returns.

When such a VM has more than 64 VPs, if the hyperv_pcpu_input_arg is not
NULL, hv_common_cpu_init() -&gt; set_memory_decrypted() -&gt; ... -&gt;
cpa_flush() -&gt; on_each_cpu() -&gt; ... -&gt; hv_send_ipi_mask() -&gt; ... -&gt;
__send_ipi_mask_ex() tries to call hv_do_rep_hypercall() with the
hyperv_pcpu_input_arg as the hypercall input page, which must be a
decrypted page in such a VM, but the page is still encrypted at this
point, and a fatal fault is triggered.

Fix the issue by setting *this_cpu_ptr(hyperv_pcpu_input_arg) after
set_memory_decrypted(): if the hyperv_pcpu_input_arg is NULL,
__send_ipi_mask_ex() returns HV_STATUS_INVALID_PARAMETER immediately,
and hv_send_ipi_mask() falls back to orig_apic.send_IPI_mask(),
which can use x2apic_send_IPI_all(), which may be slightly slower than
the hypercall but still works correctly in such a VM.

Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Reviewed-by: Tianyu Lan &lt;tiala@microsoft.com&gt;
Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Link: https://lore.kernel.org/r/20230824080712.30327-6-decui@microsoft.com
</content>
</entry>
<entry>
<title>Drivers: hv: vmbus: Support fully enlightened TDX guests</title>
<updated>2023-08-25T00:04:56+00:00</updated>
<author>
<name>Dexuan Cui</name>
<email>decui@microsoft.com</email>
</author>
<published>2023-08-24T08:07:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=68f2f2bc163d4427b04f0fb6421f091f948175fe'/>
<id>urn:sha1:68f2f2bc163d4427b04f0fb6421f091f948175fe</id>
<content type='text'>
Add Hyper-V specific code so that a fully enlightened TDX guest (i.e.
without the paravisor) can run on Hyper-V:
  Don't use hv_vp_assist_page. Use GHCI instead.
  Don't try to use the unsupported HV_REGISTER_CRASH_CTL.
  Don't trust (use) Hyper-V's TLB-flushing hypercalls.
  Don't use lazy EOI.
  Share the SynIC Event/Message pages with the hypervisor.
  Don't use the Hyper-V TSC page for now, because non-trivial work is
    required to share the page with the hypervisor.

Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Link: https://lore.kernel.org/r/20230824080712.30327-4-decui@microsoft.com
</content>
</entry>
</feed>
