kernel/linux.git/arch/x86/hyperv, branch v6.12.80

x86/hyperv: Fix error pointer dereference

2026-03-04T12:20:45+00:00

[ Upstream commit 705d01c8d78121ee1634bfc602ac4b0ad1438fab ] The function idle_thread_get() can return an error pointer and is not checked for it. Add check for error pointer. Detected by Smatch: arch/x86/hyperv/hv_vtl.c:126 hv_vtl_bringup_vcpu() error: 'idle' dereferencing possible ERR_PTR() Fixes: 2b4b90e053a29 ("x86/hyperv: Use per cpu initial stack for vtl context") Signed-off-by: Ethan Tidmore Signed-off-by: Wei Liu Signed-off-by: Sasha Levin

x86/mtrr: Rename mtrr_overwrite_state() to guest_force_mtrr_state()

2025-10-19T14:34:02+00:00

[ Upstream commit 6a5abeea9c72e1d2c538622b4cf66c80cc816fd3 ] Rename the helper to better reflect its function. Suggested-by: Dave Hansen Signed-off-by: Kirill A. Shutemov Signed-off-by: Dave Hansen Acked-by: Dave Hansen Link: https://lore.kernel.org/all/20241202073139.448208-1-kirill.shutemov%40linux.intel.com Stable-dep-of: 0dccbc75e18d ("x86/kvm: Force legacy PCI hole to UC when overriding MTRRs for TDX/SNP") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

x86/hyperv: Fix APIC ID and VP index confusion in hv_snp_boot_ap()

2025-08-01T08:48:46+00:00

[ Upstream commit 86c48271e0d60c82665e9fd61277002391efcef7 ] To start an application processor in SNP-isolated guest, a hypercall is used that takes a virtual processor index. The hv_snp_boot_ap() function uses that START_VP hypercall but passes as VP index to it what it receives as a wakeup_secondary_cpu_64 callback: the APIC ID. As those two aren't generally interchangeable, that may lead to hung APs if the VP index and the APIC ID don't match up. Update the parameter names to avoid confusion as to what the parameter is. Use the APIC ID to the VP index conversion to provide the correct input to the hypercall. Cc: stable@vger.kernel.org Fixes: 44676bb9d566 ("x86/hyperv: Add smp support for SEV-SNP guest") Signed-off-by: Roman Kisel Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20250507182227.7421-2-romank@linux.microsoft.com Signed-off-by: Wei Liu Message-ID: <20250507182227.7421-2-romank@linux.microsoft.com> [ changed HVCALL_GET_VP_INDEX_FROM_APIC_ID to HVCALL_GET_VP_ID_FROM_APIC_ID ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

x86/hyperv: Fix usage of cpu_online_mask to get valid cpu

2025-08-01T08:48:40+00:00

[ Upstream commit bb169f80ed5a156ec3405e0e49c6b8e9ae264718 ] Accessing cpu_online_mask here is problematic because the cpus read lock is not held in this context. However, cpu_online_mask isn't needed here since the effective affinity mask is guaranteed to be valid in this callback. So, just use cpumask_first() to get the cpu instead of ANDing it with cpus_online_mask unnecessarily. Fixes: e39397d1fd68 ("x86/hyperv: implement an MSI domain for root partition") Reported-by: Michael Kelley Closes: https://lore.kernel.org/linux-hyperv/SN6PR02MB4157639630F8AD2D8FD8F52FD475A@SN6PR02MB4157.namprd02.prod.outlook.com/ Suggested-by: Thomas Gleixner Signed-off-by: Nuno Das Neves Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/1751582677-30930-4-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu Message-ID: <1751582677-30930-4-git-send-email-nunodasneves@linux.microsoft.com> Signed-off-by: Sasha Levin

x86/hyperv: Fix check of return value from snp_set_vmsa()

2025-04-10T12:39:36+00:00

commit e792d843aa3c9d039074cdce728d5803262e57a7 upstream. snp_set_vmsa() returns 0 as success result and so fix it. Cc: stable@vger.kernel.org Fixes: 44676bb9d566 ("x86/hyperv: Add smp support for SEV-SNP guest") Signed-off-by: Tianyu Lan Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20250313085217.45483-1-ltykernel@gmail.com Signed-off-by: Wei Liu Message-ID: <20250313085217.45483-1-ltykernel@gmail.com> Signed-off-by: Greg Kroah-Hartman

x86/hyperv: Fix output argument to hypercall that changes page visibility

2025-04-10T12:39:31+00:00

[ Upstream commit 09beefefb57bbc3a06d98f319d85db4d719d7bcb ] The hypercall in hv_mark_gpa_visibility() is invoked with an input argument and an output argument. The output argument ostensibly returns the number of pages that were processed. But in fact, the hypercall does not provide any output, so the output argument is spurious. The spurious argument is harmless because Hyper-V ignores it, but in the interest of correctness and to avoid the potential for future problems, remove it. Signed-off-by: Michael Kelley Reviewed-by: Nuno Das Neves Link: https://lore.kernel.org/r/20250226200612.2062-2-mhklinux@outlook.com Signed-off-by: Wei Liu Message-ID: <20250226200612.2062-2-mhklinux@outlook.com> Signed-off-by: Sasha Levin

x86/hyperv/vtl: Stop kernel from probing VTL0 low memory

2025-04-10T12:39:30+00:00

[ Upstream commit 59115e2e25f42924181055ed7cc1d123af7598b7 ] For Linux, running in Hyper-V VTL (Virtual Trust Level), kernel in VTL2 tries to access VTL0 low memory in probe_roms. This memory is not described in the e820 map. Initialize probe_roms call to no-ops during boot for VTL2 kernel to avoid this. The issue got identified in OpenVMM which detects invalid accesses initiated from kernel running in VTL2. Co-developed-by: Saurabh Sengar Signed-off-by: Saurabh Sengar Signed-off-by: Naman Jain Tested-by: Roman Kisel Reviewed-by: Roman Kisel Link: https://lore.kernel.org/r/20250116061224.1701-1-namjain@linux.microsoft.com Signed-off-by: Wei Liu Message-ID: <20250116061224.1701-1-namjain@linux.microsoft.com> Signed-off-by: Sasha Levin

Merge tag 'hyperv-next-signed-20240916' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

2024-09-19T06:15:30+00:00

Pull Hyper-V updates from Wei Liu: - Optimize boot time by concurrent execution of hv_synic_init() (Saurabh Sengar) - Use helpers to read control registers in hv_snp_boot_ap() (Yosry Ahmed) - Add memory allocation check in hv_fcopy_start (Zhu Jun) * tag 'hyperv-next-signed-20240916' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: tools/hv: Add memory allocation check in hv_fcopy_start x86/hyperv: use helpers to read control registers in hv_snp_boot_ap() Drivers: hv: vmbus: Optimize boot time by concurrent execution of hv_synic_init()

Merge tag 'hyperv-fixes-signed-20240908' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

2024-09-09T16:31:55+00:00

Pull hyperv fixes from Wei Liu: - Add a documentation overview of Confidential Computing VM support (Michael Kelley) - Use lapic timer in a TDX VM without paravisor (Dexuan Cui) - Set X86_FEATURE_TSC_KNOWN_FREQ when Hyper-V provides frequency (Michael Kelley) - Fix a kexec crash due to VP assist page corruption (Anirudh Rayabharam) - Python3 compatibility fix for lsvmbus (Anthony Nandaa) - Misc fixes (Rachel Menge, Roman Kisel, zhang jiao, Hongbo Li) * tag 'hyperv-fixes-signed-20240908' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: hv: vmbus: Constify struct kobj_type and struct attribute_group tools: hv: rm .*.cmd when make clean x86/hyperv: fix kexec crash due to VP assist page corruption Drivers: hv: vmbus: Fix the misplaced function description tools: hv: lsvmbus: change shebang to use python3 x86/hyperv: Set X86_FEATURE_TSC_KNOWN_FREQ when Hyper-V provides frequency Documentation: hyperv: Add overview of Confidential Computing VM support clocksource: hyper-v: Use lapic timer in a TDX VM without paravisor Drivers: hv: Remove deprecated hv_fcopy declarations

x86/hyperv: fix kexec crash due to VP assist page corruption

2024-09-05T07:21:37+00:00

commit 9636be85cc5b ("x86/hyperv: Fix hyperv_pcpu_input_arg handling when CPUs go online/offline") introduces a new cpuhp state for hyperv initialization. cpuhp_setup_state() returns the state number if state is CPUHP_AP_ONLINE_DYN or CPUHP_BP_PREPARE_DYN and 0 for all other states. For the hyperv case, since a new cpuhp state was introduced it would return 0. However, in hv_machine_shutdown(), the cpuhp_remove_state() call is conditioned upon "hyperv_init_cpuhp > 0". This will never be true and so hv_cpu_die() won't be called on all CPUs. This means the VP assist page won't be reset. When the kexec kernel tries to setup the VP assist page again, the hypervisor corrupts the memory region of the old VP assist page causing a panic in case the kexec kernel is using that memory elsewhere. This was originally fixed in commit dfe94d4086e4 ("x86/hyperv: Fix kexec panic/hang issues"). Get rid of hyperv_init_cpuhp entirely since we are no longer using a dynamic cpuhp state and use CPUHP_AP_HYPERV_ONLINE directly with cpuhp_remove_state(). Cc: stable@vger.kernel.org Fixes: 9636be85cc5b ("x86/hyperv: Fix hyperv_pcpu_input_arg handling when CPUs go online/offline") Signed-off-by: Anirudh Rayabharam (Microsoft) Reviewed-by: Vitaly Kuznetsov Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20240828112158.3538342-1-anirudh@anirudhrb.com Signed-off-by: Wei Liu Message-ID: <20240828112158.3538342-1-anirudh@anirudhrb.com>