diff options
| author | Marc Zyngier <maz@kernel.org> | 2023-02-24 19:16:40 +0000 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2023-03-11 02:00:40 -0800 |
| commit | 47053904e18282af4525a02e3e0f519f014fc7f9 (patch) | |
| tree | e9d4feddbfbdd7ad801b6bbde0c4c5de9edbf76e /arch/arm64/kvm/hypercalls.c | |
| parent | fe15c26ee26efa11741a7b632e9f23b01aca4cc6 (diff) | |
KVM: arm64: timers: Convert per-vcpu virtual offset to a global value
Having a per-vcpu virtual offset is a pain. It needs to be synchronized
on each update, and expands badly to a setup where different timers can
have different offsets, or have composite offsets (as with NV).
So let's start by replacing the use of the CNTVOFF_EL2 shadow register
(which we want to reclaim for NV anyway), and make the virtual timer
carry a pointer to a VM-wide offset.
This simplifies the code significantly. It also addresses two terrible bugs:
- The use of CNTVOFF_EL2 leads to some nice offset corruption
when the sysreg gets reset, as reported by Joey.
- The kvm mutex is taken from a vcpu ioctl, which goes against
the locking rules...
Reported-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230224173915.GA17407@e124191.cambridge.arm.com
Tested-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20230224191640.3396734-1-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64/kvm/hypercalls.c')
| -rw-r--r-- | arch/arm64/kvm/hypercalls.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c index 64c086c02c60..5da884e11337 100644 --- a/arch/arm64/kvm/hypercalls.c +++ b/arch/arm64/kvm/hypercalls.c @@ -44,7 +44,7 @@ static void kvm_ptp_get_time(struct kvm_vcpu *vcpu, u64 *val) feature = smccc_get_arg1(vcpu); switch (feature) { case KVM_PTP_VIRT_COUNTER: - cycles = systime_snapshot.cycles - vcpu_read_sys_reg(vcpu, CNTVOFF_EL2); + cycles = systime_snapshot.cycles - vcpu->kvm->arch.timer_data.voffset; break; case KVM_PTP_PHYS_COUNTER: cycles = systime_snapshot.cycles; |