Anirudh Rayabharam (Microsoft) 2ae1beb3ab x86/hyperv: fix kexec crash due to VP assist page corruption ... commit b9af6418279c4cf73ca073f8ea024992b38be8ab upstream. commit 9636be85cc ("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 dfe94d4086 ("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: 9636be85cc ("x86/hyperv: Fix hyperv_pcpu_input_arg handling when CPUs go online/offline") Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20240828112158.3538342-1-anirudh@anirudhrb.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20240828112158.3538342-1-anirudh@anirudhrb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2024-09-18 19:24:07 +02:00
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hv_apic.c	hyperv-next for v6.6	2023-09-04 11:26:29 -07:00
hv_init.c	x86/hyperv: fix kexec crash due to VP assist page corruption	2024-09-18 19:24:07 +02:00
hv_proc.c	drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status	2021-04-21 09:49:19 +00:00
hv_spinlock.c	x86/apic: Wrap IPI calls into helper functions	2023-08-09 12:00:55 -07:00
hv_vtl.c	x86/hyperv: Use per cpu initial stack for vtl context	2024-03-26 18:20:06 -04:00
irqdomain.c	genirq: Return a const cpumask from irq_data_get_affinity_mask	2022-07-07 09:38:04 +01:00
ivm.c	hyperv-next for v6.6	2023-09-04 11:26:29 -07:00
Makefile	x86/hyperv: VTL support for Hyper-V	2023-04-18 17:29:52 +00:00
mmu.c	x86/hyperv: Improve code for referencing hyperv_pcpu_input_arg	2023-06-28 17:53:25 +00:00
nested.c	x86/hyperv: Improve code for referencing hyperv_pcpu_input_arg	2023-06-28 17:53:25 +00:00