kernel/arch/arm64/kvm/pvtime.c, branch linux-6.2.y

KVM: arm64: Use kvm_write_guest_lock when init stolen time

2020-12-03T19:02:18Z

There is a lock version kvm_write_guest. Use it to simplify code. Signed-off-by: Keqian Zhu Signed-off-by: Marc Zyngier Reviewed-by: Andrew Jones Reviewed-by: Steven Price Link: https://lore.kernel.org/r/20200817110728.12196-3-zhukeqian1@huawei.com

arm64/x86: KVM: Introduce steal-time cap

2020-08-21T13:05:19Z

arm64 requires a vcpu fd (KVM_HAS_DEVICE_ATTR vcpu ioctl) to probe support for steal-time. However this is unnecessary, as only a KVM fd is required, and it complicates userspace (userspace may prefer delaying vcpu creation until after feature probing). Introduce a cap that can be checked instead. While x86 can already probe steal-time support with a kvm fd (KVM_GET_SUPPORTED_CPUID), we add the cap there too for consistency. Signed-off-by: Andrew Jones Signed-off-by: Marc Zyngier Reviewed-by: Steven Price Link: https://lore.kernel.org/r/20200804170604.42662-7-drjones@redhat.com

KVM: arm64: pvtime: Fix stolen time accounting across migration

2020-08-21T13:04:14Z

When updating the stolen time we should always read the current stolen time from the user provided memory, not from a kernel cache. If we use a cache then we'll end up resetting stolen time to zero on the first update after migration. Signed-off-by: Andrew Jones Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200804170604.42662-5-drjones@redhat.com

KVM: arm64: Drop type input from kvm_put_guest

2020-08-21T13:04:14Z

We can use typeof() to avoid the need for the type input. Suggested-by: Marc Zyngier Signed-off-by: Andrew Jones Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200804170604.42662-4-drjones@redhat.com

KVM: arm64: pvtime: Fix potential loss of stolen time

2020-08-21T13:04:14Z

We should only check current->sched_info.run_delay once when updating stolen time. Otherwise there's a chance there could be a change between checks that we miss (preemption disabling comes after vcpu request checks). Signed-off-by: Andrew Jones Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200804170604.42662-3-drjones@redhat.com

KVM: arm64: pvtime: steal-time is only supported when configured

2020-08-21T13:04:14Z

Don't confuse the guest by saying steal-time is supported when it hasn't been configured by userspace and won't work. Signed-off-by: Andrew Jones Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200804170604.42662-2-drjones@redhat.com

KVM: arm64: pvtime: Ensure task delay accounting is enabled

2020-06-22T14:35:57Z

Ensure we're actually accounting run_delay before we claim that we'll expose it to the guest. If we're not, then we just pretend like steal time isn't supported in order to avoid any confusion. Signed-off-by: Andrew Jones Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200622142710.18677-1-drjones@redhat.com

KVM: arm64: Move virt/kvm/arm to arch/arm64

2020-05-16T14:03:59Z

Now that the 32bit KVM/arm host is a distant memory, let's move the whole of the KVM/arm64 code into the arm64 tree. As they said in the song: Welcome Home (Sanitarium). Signed-off-by: Marc Zyngier Acked-by: Will Deacon Link: https://lore.kernel.org/r/20200513104034.74741-1-maz@kernel.org