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| author | Steven Price <steven.price@arm.com> | 2019-10-21 17:28:18 +0200 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2019-10-21 20:20:28 +0200 |
| commit | 8564d6372a7d8a6d440441b8ed8020f97f744450 (patch) | |
| tree | 1ec19f1184aafb3ccfe9574f760115e170b5cb16 /virt/kvm/arm/arm.c | |
| parent | KVM: Implement kvm_put_guest() (diff) | |
| download | linux-8564d6372a7d8a6d440441b8ed8020f97f744450.tar.xz linux-8564d6372a7d8a6d440441b8ed8020f97f744450.zip | |
KVM: arm64: Support stolen time reporting via shared structure
Implement the service call for configuring a shared structure between a
VCPU and the hypervisor in which the hypervisor can write the time
stolen from the VCPU's execution time by other tasks on the host.
User space allocates memory which is placed at an IPA also chosen by user
space. The hypervisor then updates the shared structure using
kvm_put_guest() to ensure single copy atomicity of the 64-bit value
reporting the stolen time in nanoseconds.
Whenever stolen time is enabled by the guest, the stolen time counter is
reset.
The stolen time itself is retrieved from the sched_info structure
maintained by the Linux scheduler code. We enable SCHEDSTATS when
selecting KVM Kconfig to ensure this value is meaningful.
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'virt/kvm/arm/arm.c')
| -rw-r--r-- | virt/kvm/arm/arm.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index 86c6aa1cb58e..2aba375dfd13 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -40,6 +40,10 @@ #include <asm/kvm_coproc.h> #include <asm/sections.h> +#include <kvm/arm_hypercalls.h> +#include <kvm/arm_pmu.h> +#include <kvm/arm_psci.h> + #ifdef REQUIRES_VIRT __asm__(".arch_extension virt"); #endif @@ -351,6 +355,8 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) kvm_arm_reset_debug_ptr(vcpu); + kvm_arm_pvtime_vcpu_init(&vcpu->arch); + return kvm_vgic_vcpu_init(vcpu); } @@ -380,6 +386,8 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) kvm_vcpu_load_sysregs(vcpu); kvm_arch_vcpu_load_fp(vcpu); kvm_vcpu_pmu_restore_guest(vcpu); + if (kvm_arm_is_pvtime_enabled(&vcpu->arch)) + kvm_make_request(KVM_REQ_RECORD_STEAL, vcpu); if (single_task_running()) vcpu_clear_wfe_traps(vcpu); @@ -645,6 +653,9 @@ static void check_vcpu_requests(struct kvm_vcpu *vcpu) * that a VCPU sees new virtual interrupts. */ kvm_check_request(KVM_REQ_IRQ_PENDING, vcpu); + + if (kvm_check_request(KVM_REQ_RECORD_STEAL, vcpu)) + kvm_update_stolen_time(vcpu); } } |