This is called right after the memslots is updated, i.e. when the result
of update_memslots() gets installed in install_new_memslots(). Since
the memslots needs to be updated twice when we delete or move a memslot,
kvm_arch_commit_memory_region() does not correspond to this exactly.
In the following patch, x86 will use this new API to check if the mmio
generation has reached its maximum value, in which case mmio sptes need
to be flushed out.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Acked-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit e59dbe09f8)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Finally plug KVM/arm64 into the config system, making it possible
to enable KVM support on AArch64 CPUs.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit c3eb5b1444)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The virtio configuration has recently moved and is now visible everywhere.
Including the file again from KVM as we used to need earlier now causes
dependency problems:
warning: (CAIF_VIRTIO && VIRTIO_PCI && VIRTIO_MMIO && REMOTEPROC && RPMSG)
selects VIRTIO which has unmet direct dependencies (VIRTUALIZATION)
Cc: Christoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 8bd4ffd6b3)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Commit d21a1c83c7 (ARM: KVM: define KVM_ARM_MAX_VCPUS
unconditionally) changed the Kconfig logic for KVM_ARM_MAX_VCPUS to work around a
build error arising from the use of KVM_ARM_MAX_VCPUS when CONFIG_KVM=n. The
resulting Kconfig logic is a bit awkward and leaves a KVM_ARM_MAX_VCPUS always
defined in the kernel config file.
This change reverts the Kconfig logic back and adds a simple preprocessor
conditional in kvm_host.h to handle when CONFIG_KVM_ARM_MAX_VCPUS is undefined.
Signed-off-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit f2dda9d829)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
S2_PGD_SIZE defines the number of pages used by a stage-2 PGD
and is unused, except for a VM_BUG_ON check that missuses the
define.
As the check is very unlikely to ever triggered except in
circumstances where KVM is the least of our worries, just kill
both the define and the VM_BUG_ON check.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
(cherry picked from commit 4db845c3d8)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Admitedly, reading a MMIO register to load PC is very weird.
Writing PC to a MMIO register is probably even worse. But
the architecture doesn't forbid any of these, and injecting
a Prefetch Abort is the wrong thing to do anyway.
Remove this check altogether, and let the adventurous guest
wander into LaLaLand if they feel compelled to do so.
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
(cherry picked from commit 8734f16fb2)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
HYP PGDs are passed around as phys_addr_t, except just before calling
into the hypervisor init code, where they are cast to a rather weird
unsigned long long.
Just keep them around as phys_addr_t, which is what makes the most
sense.
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
(cherry picked from commit dac288f7b3)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Currently, kvmtool unconditionally declares that HVC should be used
to call PSCI, so the function numbers in the DT tell the guest
nothing about the function ID namespace or calling convention for
SMC.
We already assume that the guest will examine and honour the DT,
since there is no way it could possibly guess the KVM-specific PSCI
function IDs otherwise. So let's not encourage guests to violate
what's specified in the DT by using SMC to make the call.
[ Modified to apply to top of kvm/arm tree - Christoffer ]
Signed-off-by: Dave P Martin <Dave.Martin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
(cherry picked from commit 24a7f67575)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The arch_timer irq numbers (or PPI numbers) are implementation dependent,
so the host virtual timer irq number can be different from guest virtual
timer irq number.
This patch ensures that host virtual timer irq number is read from DTB and
guest virtual timer irq is determined based on vcpu target type.
Signed-off-by: Anup Patel <anup.patel@linaro.org>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
(cherry picked from commit 5ae7f87a56)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
HYP mode has access to some of the kernel pages. Document the
memory mapping and the offset between kernel VA and HYP VA.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit aa4a73a0a2)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Unsurprisingly, the arm64 userspace API is extremely similar to
the 32bit one, the only significant difference being the ONE_REG
register mapping.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 379e04c79e)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Wire the init of a 32bit vcpu by allowing 32bit modes in pstate,
and providing sensible defaults out of reset state.
This feature is of course conditioned by the presence of 32bit
capability on the physical CPU, and is checked by the KVM_CAP_ARM_EL1_32BIT
capability.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 0d854a60b1)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Provide the necessary infrastructure to trap coprocessor accesses that
occur when running 32bit guests.
Also wire SMC and HVC trapped in 32bit mode while were at it.
Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 62a89c4495)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Define the 32bit specific registers (SPSRs, cp15...).
Most CPU registers are directly mapped to a 64bit register
(r0->x0...). Only the SPSRs have separate registers.
cp15 registers are also mapped into their 64bit counterpart in most
cases.
Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 40033a614e)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Only the Makefile is plugged in. The Kconfig stuff is in a separate
patch to allow for an easier merge process.
Reviewed-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 6211753fdf)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
ARMv8 cores have the exact same timer as ARMv7 cores. Make sure the
KVM timer code can match it in the device tree.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit f61701e0a2)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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>
(cherry picked from commit 55c7401d92)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Provide EL2 with page tables and stack, and set the vectors
to point to the full blown world-switch code.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 092bd143cb)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Add the necessary infrastructure for identity-mapped HYP page
tables. Idmap-ed code must be in the ".hyp.idmap.text" linker
section.
The rest of the HYP ends up in ".hyp.text".
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 2240bbb697)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
To use the virtual counters from the host, we need to ensure that
CNTVOFF doesn't change unexpectedly. When we change to a guest, we
replace the host's CNTVOFF, but we don't restore it when returning to
the host.
As the host sets CNTVOFF to zero, and never changes it, we can simply
zero CNTVOFF when returning to the host. This patch adds said zeroing to
the return to host path.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Christoffer Dall <cdall@cs.columbia.edu>
(cherry picked from commit f793c23ebb)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
As KVM/arm64 is looming on the horizon, it makes sense to move some
of the common code to a single location in order to reduce duplication.
The code could live anywhere. Actually, most of KVM is already built
with a bunch of ugly ../../.. hacks in the various Makefiles, so we're
not exactly talking about style here. But maybe it is time to start
moving into a less ugly direction.
The include files must be in a "public" location, as they are accessed
from non-KVM files (arch/arm/kernel/asm-offsets.c).
For this purpose, introduce two new locations:
- virt/kvm/arm/ : x86 and ia64 already share the ioapic code in
virt/kvm, so this could be seen as a (very ugly) precedent.
- include/kvm/ : there is already an include/xen, and while the
intent is slightly different, this seems as good a location as
any
Eventually, we should probably have independant Makefiles at every
levels (just like everywhere else in the kernel), but this is just
the first step.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit 7275acdfe2)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Linux requires a number of atomic operations to provide full barrier
semantics, that is no memory accesses after the operation can be
observed before any accesses up to and including the operation in
program order.
On arm64, these operations have been incorrectly implemented as follows:
// A, B, C are independent memory locations
<Access [A]>
// atomic_op (B)
1: ldaxr x0, [B] // Exclusive load with acquire
<op(B)>
stlxr w1, x0, [B] // Exclusive store with release
cbnz w1, 1b
<Access [C]>
The assumption here being that two half barriers are equivalent to a
full barrier, so the only permitted ordering would be A -> B -> C
(where B is the atomic operation involving both a load and a store).
Unfortunately, this is not the case by the letter of the architecture
and, in fact, the accesses to A and C are permitted to pass their
nearest half barrier resulting in orderings such as Bl -> A -> C -> Bs
or Bl -> C -> A -> Bs (where Bl is the load-acquire on B and Bs is the
store-release on B). This is a clear violation of the full barrier
requirement.
The simple way to fix this is to implement the same algorithm as ARMv7
using explicit barriers:
<Access [A]>
// atomic_op (B)
dmb ish // Full barrier
1: ldxr x0, [B] // Exclusive load
<op(B)>
stxr w1, x0, [B] // Exclusive store
cbnz w1, 1b
dmb ish // Full barrier
<Access [C]>
but this has the undesirable effect of introducing *two* full barrier
instructions. A better approach is actually the following, non-intuitive
sequence:
<Access [A]>
// atomic_op (B)
1: ldxr x0, [B] // Exclusive load
<op(B)>
stlxr w1, x0, [B] // Exclusive store with release
cbnz w1, 1b
dmb ish // Full barrier
<Access [C]>
The simple observations here are:
- The dmb ensures that no subsequent accesses (e.g. the access to C)
can enter or pass the atomic sequence.
- The dmb also ensures that no prior accesses (e.g. the access to A)
can pass the atomic sequence.
- Therefore, no prior access can pass a subsequent access, or
vice-versa (i.e. A is strictly ordered before C).
- The stlxr ensures that no prior access can pass the store component
of the atomic operation.
The only tricky part remaining is the ordering between the ldxr and the
access to A, since the absence of the first dmb means that we're now
permitting re-ordering between the ldxr and any prior accesses.
From an (arbitrary) observer's point of view, there are two scenarios:
1. We have observed the ldxr. This means that if we perform a store to
[B], the ldxr will still return older data. If we can observe the
ldxr, then we can potentially observe the permitted re-ordering
with the access to A, which is clearly an issue when compared to
the dmb variant of the code. Thankfully, the exclusive monitor will
save us here since it will be cleared as a result of the store and
the ldxr will retry. Notice that any use of a later memory
observation to imply observation of the ldxr will also imply
observation of the access to A, since the stlxr/dmb ensure strict
ordering.
2. We have not observed the ldxr. This means we can perform a store
and influence the later ldxr. However, that doesn't actually tell
us anything about the access to [A], so we've not lost anything
here either when compared to the dmb variant.
This patch implements this solution for our barriered atomic operations,
ensuring that we satisfy the full barrier requirements where they are
needed.
Cc: <stable@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 8e86f0b409)
Signed-off-by: Mark Brown <broonie@linaro.org>
