linux.git/arch, branch v6.5.4 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git parisc: sba_iommu: Fix build warning if procfs if disabled 2023-09-19T10:30:27+00:00 Helge Deller deller@gmx.de 2023-08-30T05:56:04+00:00 ff4f59a022150f4a1939d9fa89aea7b767255795 [ Upstream commit 6428bc7bd3f35e43c8cb7359cb89d83248d339d2 ] Clean up the code, e.g. make proc_mckinley_root static, drop the now empty mckinley header file and remove some unneeded ifdefs around procfs functions. Signed-off-by: Helge Deller <deller@gmx.de> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202308300800.Jod4sHzM-lkp@intel.com/ Fixes: 77e0ddf097d6 ("parisc: ccio-dma: Create private runway procfs root entry") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 6428bc7bd3f35e43c8cb7359cb89d83248d339d2 ]

Clean up the code, e.g. make proc_mckinley_root static, drop the now
empty mckinley header file and remove some unneeded ifdefs around procfs
functions.

Signed-off-by: Helge Deller <deller@gmx.de>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202308300800.Jod4sHzM-lkp@intel.com/
Fixes: 77e0ddf097d6 ("parisc: ccio-dma: Create private runway procfs root entry")
Signed-off-by: Sasha Levin <sashal@kernel.org>
MIPS: Fix CONFIG_CPU_DADDI_WORKAROUNDS `modules_install' regression 2023-09-19T10:30:26+00:00 Maciej W. Rozycki macro@orcam.me.uk 2023-07-18T14:37:18+00:00 ca874c5ffad26a70b2dfd5f1fcbeaecfed129520 commit a79a404e6c2241ebc528b9ebf4c0832457b498c3 upstream. Remove a build-time check for the presence of the GCC `-msym32' option. This option has been there since GCC 4.1.0, which is below the minimum required as at commit 805b2e1d427a ("kbuild: include Makefile.compiler only when compiler is needed"), when an error message: arch/mips/Makefile:306: *** CONFIG_CPU_DADDI_WORKAROUNDS unsupported without -msym32. Stop. started to trigger for the `modules_install' target with configurations such as `decstation_64_defconfig' that set CONFIG_CPU_DADDI_WORKAROUNDS, because said commit has made `cc-option-yn' an undefined function for non-build targets. Reported-by: Jan-Benedict Glaw <jbglaw@lug-owl.de> Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Fixes: 805b2e1d427a ("kbuild: include Makefile.compiler only when compiler is needed") Cc: stable@vger.kernel.org # v5.13+ Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a79a404e6c2241ebc528b9ebf4c0832457b498c3 upstream.

Remove a build-time check for the presence of the GCC `-msym32' option.
This option has been there since GCC 4.1.0, which is below the minimum
required as at commit 805b2e1d427a ("kbuild: include Makefile.compiler
only when compiler is needed"), when an error message:

arch/mips/Makefile:306: *** CONFIG_CPU_DADDI_WORKAROUNDS unsupported without -msym32.  Stop.

started to trigger for the `modules_install' target with configurations
such as `decstation_64_defconfig' that set CONFIG_CPU_DADDI_WORKAROUNDS,
because said commit has made `cc-option-yn' an undefined function for
non-build targets.

Reported-by: Jan-Benedict Glaw <jbglaw@lug-owl.de>
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: 805b2e1d427a ("kbuild: include Makefile.compiler only when compiler is needed")
Cc: stable@vger.kernel.org # v5.13+
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
MIPS: Only fiddle with CHECKFLAGS if `need-compiler' 2023-09-19T10:30:26+00:00 Maciej W. Rozycki macro@orcam.me.uk 2023-07-18T14:37:23+00:00 20f8c9ae46a5dba4f6317d990becd5cc81f2a53c commit 4fe4a6374c4db9ae2b849b61e84b58685dca565a upstream. We have originally guarded fiddling with CHECKFLAGS in our arch Makefile by checking for the CONFIG_MIPS variable, not set for targets such as `distclean', etc. that neither include `.config' nor use the compiler. Starting from commit 805b2e1d427a ("kbuild: include Makefile.compiler only when compiler is needed") we have had a generic `need-compiler' variable explicitly telling us if the compiler will be used and thus its capabilities need to be checked and expressed in the form of compilation flags. If this variable is not set, then `make' functions such as `cc-option' are undefined, causing all kinds of weirdness to happen if we expect specific results to be returned, most recently: cc1: error: '-mloongson-mmi' must be used with '-mhard-float' messages with configurations such as `fuloong2e_defconfig' and the `modules_install' target, which does include `.config' and yet does not use the compiler. Replace the check for CONFIG_MIPS with one for `need-compiler' instead, so as to prevent the compiler from being ever called for CHECKFLAGS when not needed. Reported-by: Guillaume Tucker <guillaume.tucker@collabora.com> Closes: https://lore.kernel.org/r/85031c0c-d981-031e-8a50-bc4fad2ddcd8@collabora.com/ Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Fixes: 805b2e1d427a ("kbuild: include Makefile.compiler only when compiler is needed") Cc: stable@vger.kernel.org # v5.13+ Reported-by: "kernelci.org bot" <bot@kernelci.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4fe4a6374c4db9ae2b849b61e84b58685dca565a upstream.

We have originally guarded fiddling with CHECKFLAGS in our arch Makefile
by checking for the CONFIG_MIPS variable, not set for targets such as
`distclean', etc. that neither include `.config' nor use the compiler.

Starting from commit 805b2e1d427a ("kbuild: include Makefile.compiler
only when compiler is needed") we have had a generic `need-compiler'
variable explicitly telling us if the compiler will be used and thus its
capabilities need to be checked and expressed in the form of compilation
flags.  If this variable is not set, then `make' functions such as
`cc-option' are undefined, causing all kinds of weirdness to happen if
we expect specific results to be returned, most recently:

cc1: error: '-mloongson-mmi' must be used with '-mhard-float'

messages with configurations such as `fuloong2e_defconfig' and the
`modules_install' target, which does include `.config' and yet does not
use the compiler.

Replace the check for CONFIG_MIPS with one for `need-compiler' instead,
so as to prevent the compiler from being ever called for CHECKFLAGS when
not needed.

Reported-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Closes: https://lore.kernel.org/r/85031c0c-d981-031e-8a50-bc4fad2ddcd8@collabora.com/
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: 805b2e1d427a ("kbuild: include Makefile.compiler only when compiler is needed")
Cc: stable@vger.kernel.org # v5.13+
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
KVM: SVM: Skip VMSA init in sev_es_init_vmcb() if pointer is NULL 2023-09-19T10:30:25+00:00 Sean Christopherson seanjc@google.com 2023-08-25T02:23:57+00:00 61c97e3ee78b3244e66bd1e4c4e0a10d3b49c2dd commit 1952e74da96fb3e48b72a2d0ece78c688a5848c1 upstream. Skip initializing the VMSA physical address in the VMCB if the VMSA is NULL, which occurs during intrahost migration as KVM initializes the VMCB before copying over state from the source to the destination (including the VMSA and its physical address). In normal builds, __pa() is just math, so the bug isn't fatal, but with CONFIG_DEBUG_VIRTUAL=y, the validity of the virtual address is verified and passing in NULL will make the kernel unhappy. Fixes: 6defa24d3b12 ("KVM: SEV: Init target VMCBs in sev_migrate_from") Cc: stable@vger.kernel.org Cc: Peter Gonda <pgonda@google.com> Reviewed-by: Peter Gonda <pgonda@google.com> Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com> Link: https://lore.kernel.org/r/20230825022357.2852133-3-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1952e74da96fb3e48b72a2d0ece78c688a5848c1 upstream.

Skip initializing the VMSA physical address in the VMCB if the VMSA is
NULL, which occurs during intrahost migration as KVM initializes the VMCB
before copying over state from the source to the destination (including
the VMSA and its physical address).

In normal builds, __pa() is just math, so the bug isn't fatal, but with
CONFIG_DEBUG_VIRTUAL=y, the validity of the virtual address is verified
and passing in NULL will make the kernel unhappy.

Fixes: 6defa24d3b12 ("KVM: SEV: Init target VMCBs in sev_migrate_from")
Cc: stable@vger.kernel.org
Cc: Peter Gonda <pgonda@google.com>
Reviewed-by: Peter Gonda <pgonda@google.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Link: https://lore.kernel.org/r/20230825022357.2852133-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
KVM: SVM: Set target pCPU during IRTE update if target vCPU is running 2023-09-19T10:30:25+00:00 Sean Christopherson seanjc@google.com 2023-08-08T23:31:32+00:00 e9898d822940ac28ef38ebd21e852fba4fb68fd9 commit f3cebc75e7425d6949d726bb8e937095b0aef025 upstream. Update the target pCPU for IOMMU doorbells when updating IRTE routing if KVM is actively running the associated vCPU. KVM currently only updates the pCPU when loading the vCPU (via avic_vcpu_load()), and so doorbell events will be delayed until the vCPU goes through a put+load cycle (which might very well "never" happen for the lifetime of the VM). To avoid inserting a stale pCPU, e.g. due to racing between updating IRTE routing and vCPU load/put, get the pCPU information from the vCPU's Physical APIC ID table entry (a.k.a. avic_physical_id_cache in KVM) and update the IRTE while holding ir_list_lock. Add comments with --verbose enabled to explain exactly what is and isn't protected by ir_list_lock. Fixes: 411b44ba80ab ("svm: Implements update_pi_irte hook to setup posted interrupt") Reported-by: dengqiao.joey <dengqiao.joey@bytedance.com> Cc: stable@vger.kernel.org Cc: Alejandro Jimenez <alejandro.j.jimenez@oracle.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Maxim Levitsky <mlevitsk@redhat.com> Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Tested-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com> Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Link: https://lore.kernel.org/r/20230808233132.2499764-3-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f3cebc75e7425d6949d726bb8e937095b0aef025 upstream.

Update the target pCPU for IOMMU doorbells when updating IRTE routing if
KVM is actively running the associated vCPU.  KVM currently only updates
the pCPU when loading the vCPU (via avic_vcpu_load()), and so doorbell
events will be delayed until the vCPU goes through a put+load cycle (which
might very well "never" happen for the lifetime of the VM).

To avoid inserting a stale pCPU, e.g. due to racing between updating IRTE
routing and vCPU load/put, get the pCPU information from the vCPU's
Physical APIC ID table entry (a.k.a. avic_physical_id_cache in KVM) and
update the IRTE while holding ir_list_lock.  Add comments with --verbose
enabled to explain exactly what is and isn't protected by ir_list_lock.

Fixes: 411b44ba80ab ("svm: Implements update_pi_irte hook to setup posted interrupt")
Reported-by: dengqiao.joey <dengqiao.joey@bytedance.com>
Cc: stable@vger.kernel.org
Cc: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Tested-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Link: https://lore.kernel.org/r/20230808233132.2499764-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
KVM: nSVM: Load L1's TSC multiplier based on L1 state, not L2 state 2023-09-19T10:30:25+00:00 Sean Christopherson seanjc@google.com 2023-07-29T01:15:49+00:00 e91c07f6cf7060d2acb3aeee31a6baebe3773d3f commit 0c94e2468491cbf0754f49a5136ab51294a96b69 upstream. When emulating nested VM-Exit, load L1's TSC multiplier if L1's desired ratio doesn't match the current ratio, not if the ratio L1 is using for L2 diverges from the default. Functionally, the end result is the same as KVM will run L2 with L1's multiplier if L2's multiplier is the default, i.e. checking that L1's multiplier is loaded is equivalent to checking if L2 has a non-default multiplier. However, the assertion that TSC scaling is exposed to L1 is flawed, as userspace can trigger the WARN at will by writing the MSR and then updating guest CPUID to hide the feature (modifying guest CPUID is allowed anytime before KVM_RUN). E.g. hacking KVM's state_test selftest to do vcpu_set_msr(vcpu, MSR_AMD64_TSC_RATIO, 0); vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_TSCRATEMSR); after restoring state in a new VM+vCPU yields an endless supply of: ------------[ cut here ]------------ WARNING: CPU: 10 PID: 206939 at arch/x86/kvm/svm/nested.c:1105 nested_svm_vmexit+0x6af/0x720 [kvm_amd] Call Trace: nested_svm_exit_handled+0x102/0x1f0 [kvm_amd] svm_handle_exit+0xb9/0x180 [kvm_amd] kvm_arch_vcpu_ioctl_run+0x1eab/0x2570 [kvm] kvm_vcpu_ioctl+0x4c9/0x5b0 [kvm] ? trace_hardirqs_off+0x4d/0xa0 __se_sys_ioctl+0x7a/0xc0 __x64_sys_ioctl+0x21/0x30 do_syscall_64+0x41/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Unlike the nested VMRUN path, hoisting the svm->tsc_scaling_enabled check into the if-statement is wrong as KVM needs to ensure L1's multiplier is loaded in the above scenario. Alternatively, the WARN_ON() could simply be deleted, but that would make KVM's behavior even more subtle, e.g. it's not immediately obvious why it's safe to write MSR_AMD64_TSC_RATIO when checking only tsc_ratio_msr. Fixes: 5228eb96a487 ("KVM: x86: nSVM: implement nested TSC scaling") Cc: Maxim Levitsky <mlevitsk@redhat.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230729011608.1065019-3-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0c94e2468491cbf0754f49a5136ab51294a96b69 upstream.

When emulating nested VM-Exit, load L1's TSC multiplier if L1's desired
ratio doesn't match the current ratio, not if the ratio L1 is using for
L2 diverges from the default.  Functionally, the end result is the same
as KVM will run L2 with L1's multiplier if L2's multiplier is the default,
i.e. checking that L1's multiplier is loaded is equivalent to checking if
L2 has a non-default multiplier.

However, the assertion that TSC scaling is exposed to L1 is flawed, as
userspace can trigger the WARN at will by writing the MSR and then
updating guest CPUID to hide the feature (modifying guest CPUID is
allowed anytime before KVM_RUN).  E.g. hacking KVM's state_test
selftest to do

                vcpu_set_msr(vcpu, MSR_AMD64_TSC_RATIO, 0);
                vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_TSCRATEMSR);

after restoring state in a new VM+vCPU yields an endless supply of:

  ------------[ cut here ]------------
  WARNING: CPU: 10 PID: 206939 at arch/x86/kvm/svm/nested.c:1105
           nested_svm_vmexit+0x6af/0x720 [kvm_amd]
  Call Trace:
   nested_svm_exit_handled+0x102/0x1f0 [kvm_amd]
   svm_handle_exit+0xb9/0x180 [kvm_amd]
   kvm_arch_vcpu_ioctl_run+0x1eab/0x2570 [kvm]
   kvm_vcpu_ioctl+0x4c9/0x5b0 [kvm]
   ? trace_hardirqs_off+0x4d/0xa0
   __se_sys_ioctl+0x7a/0xc0
   __x64_sys_ioctl+0x21/0x30
   do_syscall_64+0x41/0x90
   entry_SYSCALL_64_after_hwframe+0x63/0xcd

Unlike the nested VMRUN path, hoisting the svm->tsc_scaling_enabled check
into the if-statement is wrong as KVM needs to ensure L1's multiplier is
loaded in the above scenario.   Alternatively, the WARN_ON() could simply
be deleted, but that would make KVM's behavior even more subtle, e.g. it's
not immediately obvious why it's safe to write MSR_AMD64_TSC_RATIO when
checking only tsc_ratio_msr.

Fixes: 5228eb96a487 ("KVM: x86: nSVM: implement nested TSC scaling")
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230729011608.1065019-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
KVM: nSVM: Check instead of asserting on nested TSC scaling support 2023-09-19T10:30:25+00:00 Sean Christopherson seanjc@google.com 2023-07-29T01:15:48+00:00 02b24270568f65dd607c4a848512dc8055b4491b commit 7cafe9b8e22bb3d77f130c461aedf6868c4aaf58 upstream. Check for nested TSC scaling support on nested SVM VMRUN instead of asserting that TSC scaling is exposed to L1 if L1's MSR_AMD64_TSC_RATIO has diverged from KVM's default. Userspace can trigger the WARN at will by writing the MSR and then updating guest CPUID to hide the feature (modifying guest CPUID is allowed anytime before KVM_RUN). E.g. hacking KVM's state_test selftest to do vcpu_set_msr(vcpu, MSR_AMD64_TSC_RATIO, 0); vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_TSCRATEMSR); after restoring state in a new VM+vCPU yields an endless supply of: ------------[ cut here ]------------ WARNING: CPU: 164 PID: 62565 at arch/x86/kvm/svm/nested.c:699 nested_vmcb02_prepare_control+0x3d6/0x3f0 [kvm_amd] Call Trace: <TASK> enter_svm_guest_mode+0x114/0x560 [kvm_amd] nested_svm_vmrun+0x260/0x330 [kvm_amd] vmrun_interception+0x29/0x30 [kvm_amd] svm_invoke_exit_handler+0x35/0x100 [kvm_amd] svm_handle_exit+0xe7/0x180 [kvm_amd] kvm_arch_vcpu_ioctl_run+0x1eab/0x2570 [kvm] kvm_vcpu_ioctl+0x4c9/0x5b0 [kvm] __se_sys_ioctl+0x7a/0xc0 __x64_sys_ioctl+0x21/0x30 do_syscall_64+0x41/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x45ca1b Note, the nested #VMEXIT path has the same flaw, but needs a different fix and will be handled separately. Fixes: 5228eb96a487 ("KVM: x86: nSVM: implement nested TSC scaling") Cc: Maxim Levitsky <mlevitsk@redhat.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230729011608.1065019-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7cafe9b8e22bb3d77f130c461aedf6868c4aaf58 upstream.

Check for nested TSC scaling support on nested SVM VMRUN instead of
asserting that TSC scaling is exposed to L1 if L1's MSR_AMD64_TSC_RATIO
has diverged from KVM's default.  Userspace can trigger the WARN at will
by writing the MSR and then updating guest CPUID to hide the feature
(modifying guest CPUID is allowed anytime before KVM_RUN).  E.g. hacking
KVM's state_test selftest to do

		vcpu_set_msr(vcpu, MSR_AMD64_TSC_RATIO, 0);
		vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_TSCRATEMSR);

after restoring state in a new VM+vCPU yields an endless supply of:

  ------------[ cut here ]------------
  WARNING: CPU: 164 PID: 62565 at arch/x86/kvm/svm/nested.c:699
           nested_vmcb02_prepare_control+0x3d6/0x3f0 [kvm_amd]
  Call Trace:
   <TASK>
   enter_svm_guest_mode+0x114/0x560 [kvm_amd]
   nested_svm_vmrun+0x260/0x330 [kvm_amd]
   vmrun_interception+0x29/0x30 [kvm_amd]
   svm_invoke_exit_handler+0x35/0x100 [kvm_amd]
   svm_handle_exit+0xe7/0x180 [kvm_amd]
   kvm_arch_vcpu_ioctl_run+0x1eab/0x2570 [kvm]
   kvm_vcpu_ioctl+0x4c9/0x5b0 [kvm]
   __se_sys_ioctl+0x7a/0xc0
   __x64_sys_ioctl+0x21/0x30
   do_syscall_64+0x41/0x90
   entry_SYSCALL_64_after_hwframe+0x63/0xcd
  RIP: 0033:0x45ca1b

Note, the nested #VMEXIT path has the same flaw, but needs a different
fix and will be handled separately.

Fixes: 5228eb96a487 ("KVM: x86: nSVM: implement nested TSC scaling")
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230729011608.1065019-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
KVM: SVM: Get source vCPUs from source VM for SEV-ES intrahost migration 2023-09-19T10:30:25+00:00 Sean Christopherson seanjc@google.com 2023-08-25T02:23:56+00:00 2ee4b180d51b12a45bdd3264629719ef6a572a73 commit f1187ef24eb8f36e8ad8106d22615ceddeea6097 upstream. Fix a goof where KVM tries to grab source vCPUs from the destination VM when doing intrahost migration. Grabbing the wrong vCPU not only hoses the guest, it also crashes the host due to the VMSA pointer being left NULL. BUG: unable to handle page fault for address: ffffe38687000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 39 PID: 17143 Comm: sev_migrate_tes Tainted: GO 6.5.0-smp--fff2e47e6c3b-next #151 Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 34.28.0 07/10/2023 RIP: 0010:__free_pages+0x15/0xd0 RSP: 0018:ffff923fcf6e3c78 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffe38687000000 RCX: 0000000000000100 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffe38687000000 RBP: ffff923fcf6e3c88 R08: ffff923fcafb0000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff83619b90 R12: ffff923fa9540000 R13: 0000000000080007 R14: ffff923f6d35d000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff929d0d7c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffe38687000000 CR3: 0000005224c34005 CR4: 0000000000770ee0 PKRU: 55555554 Call Trace: <TASK> sev_free_vcpu+0xcb/0x110 [kvm_amd] svm_vcpu_free+0x75/0xf0 [kvm_amd] kvm_arch_vcpu_destroy+0x36/0x140 [kvm] kvm_destroy_vcpus+0x67/0x100 [kvm] kvm_arch_destroy_vm+0x161/0x1d0 [kvm] kvm_put_kvm+0x276/0x560 [kvm] kvm_vm_release+0x25/0x30 [kvm] __fput+0x106/0x280 ____fput+0x12/0x20 task_work_run+0x86/0xb0 do_exit+0x2e3/0x9c0 do_group_exit+0xb1/0xc0 __x64_sys_exit_group+0x1b/0x20 do_syscall_64+0x41/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK> CR2: ffffe38687000000 Fixes: 6defa24d3b12 ("KVM: SEV: Init target VMCBs in sev_migrate_from") Cc: stable@vger.kernel.org Cc: Peter Gonda <pgonda@google.com> Reviewed-by: Peter Gonda <pgonda@google.com> Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com> Link: https://lore.kernel.org/r/20230825022357.2852133-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f1187ef24eb8f36e8ad8106d22615ceddeea6097 upstream.

Fix a goof where KVM tries to grab source vCPUs from the destination VM
when doing intrahost migration.  Grabbing the wrong vCPU not only hoses
the guest, it also crashes the host due to the VMSA pointer being left
NULL.

  BUG: unable to handle page fault for address: ffffe38687000000
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: 0000 [#1] SMP NOPTI
  CPU: 39 PID: 17143 Comm: sev_migrate_tes Tainted: GO       6.5.0-smp--fff2e47e6c3b-next #151
  Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 34.28.0 07/10/2023
  RIP: 0010:__free_pages+0x15/0xd0
  RSP: 0018:ffff923fcf6e3c78 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffffe38687000000 RCX: 0000000000000100
  RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffe38687000000
  RBP: ffff923fcf6e3c88 R08: ffff923fcafb0000 R09: 0000000000000000
  R10: 0000000000000000 R11: ffffffff83619b90 R12: ffff923fa9540000
  R13: 0000000000080007 R14: ffff923f6d35d000 R15: 0000000000000000
  FS:  0000000000000000(0000) GS:ffff929d0d7c0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: ffffe38687000000 CR3: 0000005224c34005 CR4: 0000000000770ee0
  PKRU: 55555554
  Call Trace:
   <TASK>
   sev_free_vcpu+0xcb/0x110 [kvm_amd]
   svm_vcpu_free+0x75/0xf0 [kvm_amd]
   kvm_arch_vcpu_destroy+0x36/0x140 [kvm]
   kvm_destroy_vcpus+0x67/0x100 [kvm]
   kvm_arch_destroy_vm+0x161/0x1d0 [kvm]
   kvm_put_kvm+0x276/0x560 [kvm]
   kvm_vm_release+0x25/0x30 [kvm]
   __fput+0x106/0x280
   ____fput+0x12/0x20
   task_work_run+0x86/0xb0
   do_exit+0x2e3/0x9c0
   do_group_exit+0xb1/0xc0
   __x64_sys_exit_group+0x1b/0x20
   do_syscall_64+0x41/0x90
   entry_SYSCALL_64_after_hwframe+0x63/0xcd
   </TASK>
  CR2: ffffe38687000000

Fixes: 6defa24d3b12 ("KVM: SEV: Init target VMCBs in sev_migrate_from")
Cc: stable@vger.kernel.org
Cc: Peter Gonda <pgonda@google.com>
Reviewed-by: Peter Gonda <pgonda@google.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Link: https://lore.kernel.org/r/20230825022357.2852133-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
KVM: SVM: Don't inject #UD if KVM attempts to skip SEV guest insn 2023-09-19T10:30:25+00:00 Sean Christopherson seanjc@google.com 2023-08-25T01:36:18+00:00 713a3ab70439babbc1e44894179086ff88ae0ae4 commit cb49631ad111570f1bad37702c11c2ae07fa2e3c upstream. Don't inject a #UD if KVM attempts to "emulate" to skip an instruction for an SEV guest, and instead resume the guest and hope that it can make forward progress. When commit 04c40f344def ("KVM: SVM: Inject #UD on attempted emulation for SEV guest w/o insn buffer") added the completely arbitrary #UD behavior, there were no known scenarios where a well-behaved guest would induce a VM-Exit that triggered emulation, i.e. it was thought that injecting #UD would be helpful. However, now that KVM (correctly) attempts to re-inject INT3/INTO, e.g. if a #NPF is encountered when attempting to deliver the INT3/INTO, an SEV guest can trigger emulation without a buffer, through no fault of its own. Resuming the guest and retrying the INT3/INTO is architecturally wrong, e.g. the vCPU will incorrectly re-hit code #DBs, but for SEV guests there is literally no other option that has a chance of making forward progress. Drop the #UD injection for all "skip" emulation, not just those related to INT3/INTO, even though that means that the guest will likely end up in an infinite loop instead of getting a #UD (the vCPU may also crash, e.g. if KVM emulated everything about an instruction except for advancing RIP). There's no evidence that suggests that an unexpected #UD is actually better than hanging the vCPU, e.g. a soft-hung vCPU can still respond to IRQs and NMIs to generate a backtrace. Reported-by: Wu Zongyo <wuzongyo@mail.ustc.edu.cn> Closes: https://lore.kernel.org/all/8eb933fd-2cf3-d7a9-32fe-2a1d82eac42a@mail.ustc.edu.cn Fixes: 6ef88d6e36c2 ("KVM: SVM: Re-inject INT3/INTO instead of retrying the instruction") Cc: stable@vger.kernel.org Cc: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20230825013621.2845700-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit cb49631ad111570f1bad37702c11c2ae07fa2e3c upstream.

Don't inject a #UD if KVM attempts to "emulate" to skip an instruction
for an SEV guest, and instead resume the guest and hope that it can make
forward progress.  When commit 04c40f344def ("KVM: SVM: Inject #UD on
attempted emulation for SEV guest w/o insn buffer") added the completely
arbitrary #UD behavior, there were no known scenarios where a well-behaved
guest would induce a VM-Exit that triggered emulation, i.e. it was thought
that injecting #UD would be helpful.

However, now that KVM (correctly) attempts to re-inject INT3/INTO, e.g. if
a #NPF is encountered when attempting to deliver the INT3/INTO, an SEV
guest can trigger emulation without a buffer, through no fault of its own.
Resuming the guest and retrying the INT3/INTO is architecturally wrong,
e.g. the vCPU will incorrectly re-hit code #DBs, but for SEV guests there
is literally no other option that has a chance of making forward progress.

Drop the #UD injection for all "skip" emulation, not just those related to
INT3/INTO, even though that means that the guest will likely end up in an
infinite loop instead of getting a #UD (the vCPU may also crash, e.g. if
KVM emulated everything about an instruction except for advancing RIP).
There's no evidence that suggests that an unexpected #UD is actually
better than hanging the vCPU, e.g. a soft-hung vCPU can still respond to
IRQs and NMIs to generate a backtrace.

Reported-by: Wu Zongyo <wuzongyo@mail.ustc.edu.cn>
Closes: https://lore.kernel.org/all/8eb933fd-2cf3-d7a9-32fe-2a1d82eac42a@mail.ustc.edu.cn
Fixes: 6ef88d6e36c2 ("KVM: SVM: Re-inject INT3/INTO instead of retrying the instruction")
Cc: stable@vger.kernel.org
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20230825013621.2845700-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
KVM: SVM: Take and hold ir_list_lock when updating vCPU's Physical ID entry 2023-09-19T10:30:25+00:00 Sean Christopherson seanjc@google.com 2023-08-08T23:31:31+00:00 133962a91462758200c6f48280fd87d919fa5f24 commit 4c08e737f056fec930b416a2bd37ed266d724f95 upstream. Hoist the acquisition of ir_list_lock from avic_update_iommu_vcpu_affinity() to its two callers, avic_vcpu_load() and avic_vcpu_put(), specifically to encapsulate the write to the vCPU's entry in the AVIC Physical ID table. This will allow a future fix to pull information from the Physical ID entry when updating the IRTE, without potentially consuming stale information, i.e. without racing with the vCPU being (un)loaded. Add a comment to call out that ir_list_lock does NOT protect against multiple writers, specifically that reading the Physical ID entry in avic_vcpu_put() outside of the lock is safe. To preserve some semblance of independence from ir_list_lock, keep the READ_ONCE() in avic_vcpu_load() even though acuiring the spinlock effectively ensures the load(s) will be generated after acquiring the lock. Cc: stable@vger.kernel.org Tested-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com> Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Link: https://lore.kernel.org/r/20230808233132.2499764-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4c08e737f056fec930b416a2bd37ed266d724f95 upstream.

Hoist the acquisition of ir_list_lock from avic_update_iommu_vcpu_affinity()
to its two callers, avic_vcpu_load() and avic_vcpu_put(), specifically to
encapsulate the write to the vCPU's entry in the AVIC Physical ID table.
This will allow a future fix to pull information from the Physical ID entry
when updating the IRTE, without potentially consuming stale information,
i.e. without racing with the vCPU being (un)loaded.

Add a comment to call out that ir_list_lock does NOT protect against
multiple writers, specifically that reading the Physical ID entry in
avic_vcpu_put() outside of the lock is safe.

To preserve some semblance of independence from ir_list_lock, keep the
READ_ONCE() in avic_vcpu_load() even though acuiring the spinlock
effectively ensures the load(s) will be generated after acquiring the
lock.

Cc: stable@vger.kernel.org
Tested-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Link: https://lore.kernel.org/r/20230808233132.2499764-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>