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| author | Marc Zyngier <marc.zyngier@arm.com> | 2015-09-16 16:18:59 +0100 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2015-09-30 11:00:04 +0200 |
| commit | eaebd1fba83da84665c38195ef977647adf3dc5c (patch) | |
| tree | 93dceccf2a08bbbc68530a650c379c69c038cdc3 | |
| parent | 86230818ac7bb48f7821d9c41d96a1233c4535c3 (diff) | |
| download | lwn-eaebd1fba83da84665c38195ef977647adf3dc5c.tar.gz lwn-eaebd1fba83da84665c38195ef977647adf3dc5c.zip | |
arm64: KVM: Disable virtual timer even if the guest is not using it
commit c4cbba9fa078f55d9f6d081dbb4aec7cf969e7c7 upstream.
When running a guest with the architected timer disabled (with QEMU and
the kernel_irqchip=off option, for example), it is important to make
sure the timer gets turned off. Otherwise, the guest may try to
enable it anyway, leading to a screaming HW interrupt.
The fix is to unconditionally turn off the virtual timer on guest
exit.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| -rw-r--r-- | arch/arm64/kvm/hyp.S | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index a255167baf6a..44b00eb7b340 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -472,8 +472,6 @@ __kvm_hyp_code_start: mrs x3, cntv_ctl_el0 and x3, x3, #3 str w3, [x0, #VCPU_TIMER_CNTV_CTL] - bic x3, x3, #1 // Clear Enable - msr cntv_ctl_el0, x3 isb @@ -481,6 +479,9 @@ __kvm_hyp_code_start: str x3, [x0, #VCPU_TIMER_CNTV_CVAL] 1: + // Disable the virtual timer + msr cntv_ctl_el0, xzr + // Allow physical timer/counter access for the host mrs x2, cnthctl_el2 orr x2, x2, #3 |