In order to ensure completion of inner-shareable maintenance instructions
(cache and TLB) on AArch64, we can use the -ish suffix to the dsb
instruction.
This patch relaxes our dsb sy instructions to dsb ish where possible.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Commit 1fcf7ce0c6 (arm: kvm: implement CPU PM notifier) added
support for CPU power-management, using a cpu_notifier to re-init
KVM on a CPU that entered CPU idle.
The code assumed that a CPU entering idle would actually be powered
off, loosing its state entierely, and would then need to be
reinitialized. It turns out that this is not always the case, and
some HW performs CPU PM without actually killing the core. In this
case, we try to reinitialize KVM while it is still live. It ends up
badly, as reported by Andre Przywara (using a Calxeda Midway):
[ 3.663897] Kernel panic - not syncing: unexpected prefetch abort in Hyp mode at: 0x685760
[ 3.663897] unexpected data abort in Hyp mode at: 0xc067d150
[ 3.663897] unexpected HVC/SVC trap in Hyp mode at: 0xc0901dd0
The trick here is to detect if we've been through a full re-init or
not by looking at HVBAR (VBAR_EL2 on arm64). This involves
implementing the backend for __hyp_get_vectors in the main KVM HYP
code (rather small), and checking the return value against the
default one when the CPU notifier is called on CPU_PM_EXIT.
Reported-by: Andre Przywara <osp@andrep.de>
Tested-by: Andre Przywara <osp@andrep.de>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Rob Herring <rob.herring@linaro.org>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Ensure that accesses to the GICH_* registers are byteswapped
when the kernel is compiled as big-endian.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
When performing a Stage-2 TLB invalidation, it is necessary to
make sure the write to the page tables is observable by all CPUs.
For this purpose, add dsb instructions to __kvm_tlb_flush_vmid_ipa
and __kvm_flush_vm_context before doing the TLB invalidation itself.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Not saving PAR_EL1 is an unfortunate oversight. If the guest
performs an AT* operation and gets scheduled out before reading
the result of the translation from PAREL1, it could become
corrupted by another guest or the host.
Saving this register is made slightly more complicated as KVM also
uses it on the permission fault handling path, leading to an ugly
"stash and restore" sequence. Fortunately, this is already a slow
path so we don't really care. Also, Linux doesn't do any AT*
operation, so Linux guests are not impacted by this bug.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Allow registers specific to 32bit guests to be saved/restored
during the world switch.
Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Add support for the in-kernel timer emulation.
Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Add support for the in-kernel GIC emulation.
Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
The HYP mode world switch in all its glory.
Implements save/restore of host/guest registers, EL2 trapping,
IPA resolution, and additional services (tlb invalidation).
Reviewed-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Will Deacon
Marc Zyngier