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authorMarc Zyngier <maz@kernel.org>2023-02-24 19:16:40 +0000
committerOliver Upton <oliver.upton@linux.dev>2023-03-11 02:00:40 -0800
commit47053904e18282af4525a02e3e0f519f014fc7f9 (patch)
treee9d4feddbfbdd7ad801b6bbde0c4c5de9edbf76e /include/kvm
parentfe15c26ee26efa11741a7b632e9f23b01aca4cc6 (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 'include/kvm')
-rw-r--r--include/kvm/arm_arch_timer.h15
1 files changed, 15 insertions, 0 deletions
diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h
index 71916de7c6c4..c52a6e6839da 100644
--- a/include/kvm/arm_arch_timer.h
+++ b/include/kvm/arm_arch_timer.h
@@ -23,6 +23,19 @@ enum kvm_arch_timer_regs {
TIMER_REG_CTL,
};
+struct arch_timer_offset {
+ /*
+ * If set, pointer to one of the offsets in the kvm's offset
+ * structure. If NULL, assume a zero offset.
+ */
+ u64 *vm_offset;
+};
+
+struct arch_timer_vm_data {
+ /* Offset applied to the virtual timer/counter */
+ u64 voffset;
+};
+
struct arch_timer_context {
struct kvm_vcpu *vcpu;
@@ -32,6 +45,8 @@ struct arch_timer_context {
/* Emulated Timer (may be unused) */
struct hrtimer hrtimer;
+ /* Offset for this counter/timer */
+ struct arch_timer_offset offset;
/*
* We have multiple paths which can save/restore the timer state onto
* the hardware, so we need some way of keeping track of where the