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authorMarc Zyngier <maz@kernel.org>2023-08-22 15:18:10 +0300
committerMarc Zyngier <maz@kernel.org>2023-10-12 18:55:21 +0300
commit9404673293b065cbb16b8915530147cac7e80b4d (patch)
tree4bdefb73667c09dec5cccd26c97cf59f37f2cd92 /include/kvm
parent839d90357b7ce6b129045d28ac22bd3a247e2350 (diff)
downloadlinux-9404673293b065cbb16b8915530147cac7e80b4d.tar.xz
KVM: arm64: timers: Correctly handle TGE flip with CNTPOFF_EL2
Contrary to common belief, HCR_EL2.TGE has a direct and immediate effect on the way the EL0 physical counter is offset. Flipping TGE from 1 to 0 while at EL2 immediately changes the way the counter compared to the CVAL limit. This means that we cannot directly save/restore the guest's view of CVAL, but that we instead must treat it as if CNTPOFF didn't exist. Only in the world switch, once we figure out that we do have CNTPOFF, can we must the offset back and forth depending on the polarity of TGE. Fixes: 2b4825a86940 ("KVM: arm64: timers: Use CNTPOFF_EL2 to offset the physical timer") Reported-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> Tested-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'include/kvm')
-rw-r--r--include/kvm/arm_arch_timer.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h
index bb3cb005873e..e748bc957d83 100644
--- a/include/kvm/arm_arch_timer.h
+++ b/include/kvm/arm_arch_timer.h
@@ -82,6 +82,8 @@ struct timer_map {
struct arch_timer_context *emul_ptimer;
};
+void get_timer_map(struct kvm_vcpu *vcpu, struct timer_map *map);
+
struct arch_timer_cpu {
struct arch_timer_context timers[NR_KVM_TIMERS];
@@ -145,4 +147,9 @@ u64 timer_get_cval(struct arch_timer_context *ctxt);
void kvm_timer_cpu_up(void);
void kvm_timer_cpu_down(void);
+static inline bool has_cntpoff(void)
+{
+ return (has_vhe() && cpus_have_final_cap(ARM64_HAS_ECV_CNTPOFF));
+}
+
#endif