kernel/arch/powerpc/include/asm/kvm_guest.h, branch linux-6.2.y

powerpc/kernel: Add __init attribute to eligible functions

2021-12-23T11:33:10Z

Some functions defined in `arch/powerpc/kernel` (and one in `arch/powerpc/ kexec`) are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by: Nick Child Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211216220035.605465-2-nick.child@ibm.com

powerpc: Fix is_kvm_guest() / kvm_para_available()

2021-06-25T04:47:19Z

Commit a21d1becaa3f ("powerpc: Reintroduce is_kvm_guest() as a fast-path check") added is_kvm_guest() and changed kvm_para_available() to use it. is_kvm_guest() checks a static key, kvm_guest, and that static key is set in check_kvm_guest(). The problem is check_kvm_guest() is only called on pseries, and even then only in some configurations. That means is_kvm_guest() always returns false on all non-pseries and some pseries depending on configuration. That's a bug. For PR KVM guests this is noticable because they no longer do live patching of themselves, which can be detected by the omission of a message in dmesg such as: KVM: Live patching for a fast VM worked To fix it make check_kvm_guest() an initcall, to ensure it's always called at boot. It needs to be core so that it runs before kvm_guest_init() which is postcore. To be an initcall it needs to return int, where 0 means success, so update that. We still call it manually in pSeries_smp_probe(), because that runs before init calls are run. Fixes: a21d1becaa3f ("powerpc: Reintroduce is_kvm_guest() as a fast-path check") Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210623130514.2543232-1-mpe@ellerman.id.au

powerpc: Reintroduce is_kvm_guest() as a fast-path check

2020-12-03T14:01:22Z

Introduce a static branch that would be set during boot if the OS happens to be a KVM guest. Subsequent checks to see if we are on KVM will rely on this static branch. This static branch would be used in vcpu_is_preempted() in a subsequent patch. Signed-off-by: Srikar Dronamraju Acked-by: Waiman Long Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201202050456.164005-4-srikar@linux.vnet.ibm.com

powerpc: Rename is_kvm_guest() to check_kvm_guest()

2020-12-03T14:01:21Z

We want to reuse the is_kvm_guest() name in a subsequent patch but with a new body. Hence rename is_kvm_guest() to check_kvm_guest(). No additional changes. Signed-off-by: Srikar Dronamraju Acked-by: Waiman Long Signed-off-by: kernel test robot # int -> bool fix [mpe: Fold in fix from lkp to use true/false not 0/1] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201202050456.164005-3-srikar@linux.vnet.ibm.com

powerpc: Refactor is_kvm_guest() declaration to new header

2020-12-03T14:01:21Z

Only code/declaration movement, in anticipation of doing a KVM-aware vcpu_is_preempted(). No additional changes. Signed-off-by: Srikar Dronamraju Acked-by: Waiman Long Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201202050456.164005-2-srikar@linux.vnet.ibm.com