Michael Kelley 9636be85cc x86/hyperv: Fix hyperv_pcpu_input_arg handling when CPUs go online/offline ... These commits a494aef23d ("PCI: hv: Replace retarget_msi_interrupt_params with hyperv_pcpu_input_arg") 2c6ba42168 ("PCI: hv: Enable PCI pass-thru devices in Confidential VMs") update the Hyper-V virtual PCI driver to use the hyperv_pcpu_input_arg because that memory will be correctly marked as decrypted or encrypted for all VM types (CoCo or normal). But problems ensue when CPUs in the VM go online or offline after virtual PCI devices have been configured. When a CPU is brought online, the hyperv_pcpu_input_arg for that CPU is initialized by hv_cpu_init() running under state CPUHP_AP_ONLINE_DYN. But this state occurs after state CPUHP_AP_IRQ_AFFINITY_ONLINE, which may call the virtual PCI driver and fault trying to use the as yet uninitialized hyperv_pcpu_input_arg. A similar problem occurs in a CoCo VM if the MMIO read and write hypercalls are used from state CPUHP_AP_IRQ_AFFINITY_ONLINE. When a CPU is taken offline, IRQs may be reassigned in state CPUHP_TEARDOWN_CPU. Again, the virtual PCI driver may fault trying to use the hyperv_pcpu_input_arg that has already been freed by a higher state. Fix the onlining problem by adding state CPUHP_AP_HYPERV_ONLINE immediately after CPUHP_AP_ONLINE_IDLE (similar to CPUHP_AP_KVM_ONLINE) and before CPUHP_AP_IRQ_AFFINITY_ONLINE. Use this new state for Hyper-V initialization so that hyperv_pcpu_input_arg is allocated early enough. Fix the offlining problem by not freeing hyperv_pcpu_input_arg when a CPU goes offline. Retain the allocated memory, and reuse it if the CPU comes back online later. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Dexuan Cui <decui@microsoft.com> Link: https://lore.kernel.org/r/1684862062-51576-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>		2023-06-17 23:09:47 +00:00
..
hv_apic.c	x86/hyperv: Add callback filter to cpumask_to_vpset()	2023-04-17 19:19:05 +00:00
hv_init.c	x86/hyperv: Fix hyperv_pcpu_input_arg handling when CPUs go online/offline	2023-06-17 23:09:47 +00:00
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/hyperv: Fix unused variable 'msr_val' warning in hv_qlock_wait	2021-03-24 11:31:04 +00:00
hv_vtl.c	x86/hyperv/vtl: Add noop for realmode pointers	2023-05-08 16:46:43 +00:00
irqdomain.c	genirq: Return a const cpumask from irq_data_get_affinity_mask	2022-07-07 09:38:04 +01:00
ivm.c	Objtool changes for v6.4:	2023-04-28 14:02:54 -07:00
Makefile	x86/hyperv: VTL support for Hyper-V	2023-04-18 17:29:52 +00:00
mmu.c	x86/hyperv: Exclude lazy TLB mode CPUs from enlightened TLB flushes	2023-04-17 19:19:05 +00:00
nested.c	drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status	2021-04-21 09:49:19 +00:00