Dave Martin b045e4d0f3 KVM: arm64: Don't mask softirq with IRQs disabled in vcpu_put() ... Commit e6b673b ("KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing") introduces a specific helper kvm_arch_vcpu_put_fp() for saving the vcpu FPSIMD state during vcpu_put(). This function uses local_bh_disable()/_enable() to protect the FPSIMD context manipulation from interruption by softirqs. This approach is not correct, because vcpu_put() can be invoked either from the KVM host vcpu thread (when exiting the vcpu run loop), or via a preempt notifier. In the former case, only preemption is disabled. In the latter case, the function is called from inside __schedule(), which means that IRQs are disabled. Use of local_bh_disable()/_enable() with IRQs disabled is considerd an error, resulting in lockdep splats while running VMs if lockdep is enabled. This patch disables IRQs instead of attempting to disable softirqs, avoiding the problem of calling local_bh_enable() with IRQs disabled in the __schedule() path. This creates an additional interrupt blackout during vcpu run loop exit, but this is the rare case and the blackout latency is still less than that of __schedule(). Fixes: e6b673b741 ("KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing") Reported-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>		2018-06-21 09:14:44 +01:00
..
boot	ARM: SoC: late updates	2018-06-11 18:19:45 -07:00
configs	ARM: SoC platform updates	2018-06-11 17:49:09 -07:00
crypto	crypto: clarify licensing of OpenSSL asm code	2018-05-31 00:13:44 +08:00
include	arm64: Introduce sysreg_clear_set()	2018-06-21 09:14:54 +01:00
kernel	Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables	2018-06-14 12:21:18 +09:00
kvm	KVM: arm64: Don't mask softirq with IRQs disabled in vcpu_put()	2018-06-21 09:14:44 +01:00
lib	arm64: export tishift functions to modules	2018-05-21 19:00:48 +01:00
mm	treewide: use PHYS_ADDR_MAX to avoid type casting ULLONG_MAX	2018-06-15 07:55:25 +09:00
net	bpf, arm64: save 4 bytes in prologue when ebpf insns came from cbpf	2018-05-14 19:11:45 -07:00
xen	arm64: mm: Add additional parameter to uaccess_ttbr0_disable	2018-01-17 13:57:49 +01:00
Kconfig	Kbuild: rename HAVE_CC_STACKPROTECTOR config variable	2018-06-15 07:15:28 +09:00
Kconfig.debug
Kconfig.platforms	arm64: dts: renesas: Add Renesas R8A77990 Kconfig support	2018-05-16 10:44:01 +02:00
Makefile	arm64: move GCC version check for ARCH_SUPPORTS_INT128 to Kconfig	2018-06-08 18:56:02 +09:00