linux.git/arch, branch v5.4.252 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git x86: fix backwards merge of GDS/SRSO bit 2023-08-08T17:56:37+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2023-08-08T17:20:48+00:00 9399ea1ce48162091fb88b162e40a9e3fbb103e5 Stable-tree-only change. Due to the way the GDS and SRSO patches flowed into the stable tree, it was a 50% chance that the merge of the which value GDS and SRSO should be. Of course, I lost that bet, and chose the opposite of what Linus chose in commit 64094e7e3118 ("Merge tag 'gds-for-linus-2023-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip") Fix this up by switching the values to match what is now in Linus's tree as that is the correct value to mirror. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Stable-tree-only change.

Due to the way the GDS and SRSO patches flowed into the stable tree, it
was a 50% chance that the merge of the which value GDS and SRSO should
be.  Of course, I lost that bet, and chose the opposite of what Linus
chose in commit 64094e7e3118 ("Merge tag 'gds-for-linus-2023-08-01' of
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip")

Fix this up by switching the values to match what is now in Linus's tree
as that is the correct value to mirror.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/cpu, kvm: Add support for CPUID_80000021_EAX 2023-08-08T17:56:37+00:00 Kim Phillips kim.phillips@amd.com 2023-01-10T22:46:37+00:00 43ed6f79b3e7cb1587ee61686bf8882d254a481c commit 8415a74852d7c24795007ee9862d25feb519007c upstream. Add support for CPUID leaf 80000021, EAX. The majority of the features will be used in the kernel and thus a separate leaf is appropriate. Include KVM's reverse_cpuid entry because features are used by VM guests, too. [ bp: Massage commit message. ] Signed-off-by: Kim Phillips <kim.phillips@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20230124163319.2277355-2-kim.phillips@amd.com [bwh: Backported to 6.1: adjust context] Signed-off-by: Ben Hutchings <benh@debian.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8415a74852d7c24795007ee9862d25feb519007c upstream.

Add support for CPUID leaf 80000021, EAX. The majority of the features will be
used in the kernel and thus a separate leaf is appropriate.

Include KVM's reverse_cpuid entry because features are used by VM guests, too.

  [ bp: Massage commit message. ]

Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20230124163319.2277355-2-kim.phillips@amd.com
[bwh: Backported to 6.1: adjust context]
Signed-off-by: Ben Hutchings <benh@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/bugs: Increase the x86 bugs vector size to two u32s 2023-08-08T17:56:37+00:00 Borislav Petkov (AMD) bp@alien8.de 2023-07-08T08:21:35+00:00 1f0618bb24563aaa51473f23863b1e09bbf2ff2c Upstream commit: 0e52740ffd10c6c316837c6c128f460f1aaba1ea There was never a doubt in my mind that they would not fit into a single u32 eventually. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Upstream commit: 0e52740ffd10c6c316837c6c128f460f1aaba1ea

There was never a doubt in my mind that they would not fit into a single
u32 eventually.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/cpufeatures: Assign dedicated feature word for CPUID_0x8000001F[EAX] 2023-08-08T17:56:36+00:00 Sean Christopherson seanjc@google.com 2021-01-22T20:40:46+00:00 694b40dcfb41a691ce56ce164d8039b05071fc41 commit fb35d30fe5b06cc24444f0405da8fbe0be5330d1 upstream. Collect the scattered SME/SEV related feature flags into a dedicated word. There are now five recognized features in CPUID.0x8000001F.EAX, with at least one more on the horizon (SEV-SNP). Using a dedicated word allows KVM to use its automagic CPUID adjustment logic when reporting the set of supported features to userspace. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Brijesh Singh <brijesh.singh@amd.com> Link: https://lkml.kernel.org/r/20210122204047.2860075-2-seanjc@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit fb35d30fe5b06cc24444f0405da8fbe0be5330d1 upstream.

Collect the scattered SME/SEV related feature flags into a dedicated
word.  There are now five recognized features in CPUID.0x8000001F.EAX,
with at least one more on the horizon (SEV-SNP).  Using a dedicated word
allows KVM to use its automagic CPUID adjustment logic when reporting
the set of supported features to userspace.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Link: https://lkml.kernel.org/r/20210122204047.2860075-2-seanjc@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/cpu: Add VM page flush MSR availablility as a CPUID feature 2023-08-08T17:56:36+00:00 Tom Lendacky thomas.lendacky@amd.com 2020-12-10T17:09:36+00:00 4fa849d4af687540e1c4d8309bea15ec613279d1 commit 69372cf01290b9587d2cee8fbe161d75d55c3adc upstream. On systems that do not have hardware enforced cache coherency between encrypted and unencrypted mappings of the same physical page, the hypervisor can use the VM page flush MSR (0xc001011e) to flush the cache contents of an SEV guest page. When a small number of pages are being flushed, this can be used in place of issuing a WBINVD across all CPUs. CPUID 0x8000001f_eax[2] is used to determine if the VM page flush MSR is available. Add a CPUID feature to indicate it is supported and define the MSR. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Message-Id: <f1966379e31f9b208db5257509c4a089a87d33d0.1607620209.git.thomas.lendacky@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 69372cf01290b9587d2cee8fbe161d75d55c3adc upstream.

On systems that do not have hardware enforced cache coherency between
encrypted and unencrypted mappings of the same physical page, the
hypervisor can use the VM page flush MSR (0xc001011e) to flush the cache
contents of an SEV guest page. When a small number of pages are being
flushed, this can be used in place of issuing a WBINVD across all CPUs.

CPUID 0x8000001f_eax[2] is used to determine if the VM page flush MSR is
available. Add a CPUID feature to indicate it is supported and define the
MSR.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <f1966379e31f9b208db5257509c4a089a87d33d0.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/cpufeatures: Add SEV-ES CPU feature 2023-08-08T17:56:36+00:00 Tom Lendacky thomas.lendacky@amd.com 2020-09-07T13:15:06+00:00 998eec0666074375eafc70920eeb5988ab2b2026 commit 360e7c5c4ca4fd8e627781ed42f95d58bc3bb732 upstream. Add CPU feature detection for Secure Encrypted Virtualization with Encrypted State. This feature enhances SEV by also encrypting the guest register state, making it in-accessible to the hypervisor. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-6-joro@8bytes.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 360e7c5c4ca4fd8e627781ed42f95d58bc3bb732 upstream.

Add CPU feature detection for Secure Encrypted Virtualization with
Encrypted State. This feature enhances SEV by also encrypting the
guest register state, making it in-accessible to the hypervisor.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200907131613.12703-6-joro@8bytes.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/mm: Use mm_alloc() in poking_init() 2023-08-08T17:56:36+00:00 Peter Zijlstra peterz@infradead.org 2022-10-25T19:38:21+00:00 3d1b8cfdd0c9e2d941f96b09738472ecf91bc599 commit 3f4c8211d982099be693be9aa7d6fc4607dff290 upstream. Instead of duplicating init_mm, allocate a fresh mm. The advantage is that mm_alloc() has much simpler dependencies. Additionally it makes more conceptual sense, init_mm has no (and must not have) user state to duplicate. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20221025201057.816175235@infradead.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3f4c8211d982099be693be9aa7d6fc4607dff290 upstream.

Instead of duplicating init_mm, allocate a fresh mm. The advantage is
that mm_alloc() has much simpler dependencies. Additionally it makes
more conceptual sense, init_mm has no (and must not have) user state
to duplicate.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221025201057.816175235@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/mm: fix poking_init() for Xen PV guests 2023-08-08T17:56:36+00:00 Juergen Gross jgross@suse.com 2023-01-09T15:09:22+00:00 ddcf05fe8850110fe521845b995dd1867d7517b7 commit 26ce6ec364f18d2915923bc05784084e54a5c4cc upstream. Commit 3f4c8211d982 ("x86/mm: Use mm_alloc() in poking_init()") broke the kernel for running as Xen PV guest. It seems as if the new address space is never activated before being used, resulting in Xen rejecting to accept the new CR3 value (the PGD isn't pinned). Fix that by adding the now missing call of paravirt_arch_dup_mmap() to poking_init(). That call was previously done by dup_mm()->dup_mmap() and it is a NOP for all cases but for Xen PV, where it is just doing the pinning of the PGD. Fixes: 3f4c8211d982 ("x86/mm: Use mm_alloc() in poking_init()") Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230109150922.10578-1-jgross@suse.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 26ce6ec364f18d2915923bc05784084e54a5c4cc upstream.

Commit 3f4c8211d982 ("x86/mm: Use mm_alloc() in poking_init()") broke
the kernel for running as Xen PV guest.

It seems as if the new address space is never activated before being
used, resulting in Xen rejecting to accept the new CR3 value (the PGD
isn't pinned).

Fix that by adding the now missing call of paravirt_arch_dup_mmap() to
poking_init(). That call was previously done by dup_mm()->dup_mmap() and
it is a NOP for all cases but for Xen PV, where it is just doing the
pinning of the PGD.

Fixes: 3f4c8211d982 ("x86/mm: Use mm_alloc() in poking_init()")
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230109150922.10578-1-jgross@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/xen: Fix secondary processors' FPU initialization 2023-08-08T17:56:35+00:00 Juergen Gross jgross@suse.com 2023-07-03T13:00:32+00:00 3f8968f1f0ad259591a0f050372c4abe3aa9b067 commit fe3e0a13e597c1c8617814bf9b42ab732db5c26e upstream. Moving the call of fpu__init_cpu() from cpu_init() to start_secondary() broke Xen PV guests, as those don't call start_secondary() for APs. Call fpu__init_cpu() in Xen's cpu_bringup(), which is the Xen PV replacement of start_secondary(). Fixes: b81fac906a8f ("x86/fpu: Move FPU initialization into arch_cpu_finalize_init()") Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230703130032.22916-1-jgross@suse.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit fe3e0a13e597c1c8617814bf9b42ab732db5c26e upstream.

Moving the call of fpu__init_cpu() from cpu_init() to start_secondary()
broke Xen PV guests, as those don't call start_secondary() for APs.

Call fpu__init_cpu() in Xen's cpu_bringup(), which is the Xen PV
replacement of start_secondary().

Fixes: b81fac906a8f ("x86/fpu: Move FPU initialization into arch_cpu_finalize_init()")
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230703130032.22916-1-jgross@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
KVM: Add GDS_NO support to KVM 2023-08-08T17:56:35+00:00 Daniel Sneddon daniel.sneddon@linux.intel.com 2023-07-13T02:43:14+00:00 e56c1e0f91343007dbeb5e05e0b09f5c9e8a5560 commit 81ac7e5d741742d650b4ed6186c4826c1a0631a7 upstream Gather Data Sampling (GDS) is a transient execution attack using gather instructions from the AVX2 and AVX512 extensions. This attack allows malicious code to infer data that was previously stored in vector registers. Systems that are not vulnerable to GDS will set the GDS_NO bit of the IA32_ARCH_CAPABILITIES MSR. This is useful for VM guests that may think they are on vulnerable systems that are, in fact, not affected. Guests that are running on affected hosts where the mitigation is enabled are protected as if they were running on an unaffected system. On all hosts that are not affected or that are mitigated, set the GDS_NO bit. Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 81ac7e5d741742d650b4ed6186c4826c1a0631a7 upstream

Gather Data Sampling (GDS) is a transient execution attack using
gather instructions from the AVX2 and AVX512 extensions. This attack
allows malicious code to infer data that was previously stored in
vector registers. Systems that are not vulnerable to GDS will set the
GDS_NO bit of the IA32_ARCH_CAPABILITIES MSR. This is useful for VM
guests that may think they are on vulnerable systems that are, in
fact, not affected. Guests that are running on affected hosts where
the mitigation is enabled are protected as if they were running
on an unaffected system.

On all hosts that are not affected or that are mitigated, set the
GDS_NO bit.

Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>