Commit 523f0e5421 ("KVM: PPC: E500:
Explicitly mark shadow maps invalid") began using E500_TLB_VALID
for guest TLB1 entries, and skipping invalidations if it's not set.
However, when E500_TLB_VALID was set for such entries, it was on a
fake local ref, and so the invalidations never happen. gtlb_privs
is documented as being only for guest TLB0, though we already violate
that with E500_TLB_BITMAP.
Now that we have MMU notifiers, and thus don't need to actually
retain a reference to the mapped pages, get rid of tlb_refs, and
use gtlb_privs for E500_TLB_VALID in TLB1.
Since we can have more than one host TLB entry for a given tlbe_ref,
be careful not to clear existing flags that are relevant to other
host TLB entries when preparing a new host TLB entry.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
It's possible that we're using the same host TLB1 slot to map (a
presumably different portion of) the same guest TLB1 entry. Clear
the bit in the map before setting it, so that if the esels are the same
the bit will remain set.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Add one to esel values in h2g_tlb1_rmap, so that "no mapping" can be
distinguished from "esel 0". Note that we're not saved by the fact
that host esel 0 is reserved for non-KVM use, because KVM host esel
numbering is not the raw host numbering (see to_htlb1_esel).
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
The existing check handles the case where we've migrated to a different
core than we last ran on, but it doesn't handle the case where we're
still on the same cpu we last ran on, but some other vcpu has run on
this cpu in the meantime.
Without this, guest segfaults (and other misbehavior) have been seen in
smp guests.
Cc: stable@vger.kernel.org # 3.8.x
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Now we use ESID_BITS of kernel address to build proto vsid. So rename
USER_ESIT_BITS to ESID_BITS
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: <stable@vger.kernel.org> [v3.8]
I'm not sure why, but the hlist for each entry iterators were conceived
list_for_each_entry(pos, head, member)
The hlist ones were greedy and wanted an extra parameter:
hlist_for_each_entry(tpos, pos, head, member)
Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.
Besides the semantic patch, there was some manual work required:
- Fix up the actual hlist iterators in linux/list.h
- Fix up the declaration of other iterators based on the hlist ones.
- A very small amount of places were using the 'node' parameter, this
was modified to use 'obj->member' instead.
- Coccinelle didn't handle the hlist_for_each_entry_safe iterator
properly, so those had to be fixed up manually.
The semantic patch which is mostly the work of Peter Senna Tschudin is here:
@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;
type T;
expression a,c,d,e;
identifier b;
statement S;
@@
-T b;
<+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
...+>
[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull powerpc updates from Benjamin Herrenschmidt:
"So from the depth of frozen Minnesota, here's the powerpc pull request
for 3.9. It has a few interesting highlights, in addition to the
usual bunch of bug fixes, minor updates, embedded device tree updates
and new boards:
- Hand tuned asm implementation of SHA1 (by Paulus & Michael
Ellerman)
- Support for Doorbell interrupts on Power8 (kind of fast
thread-thread IPIs) by Ian Munsie
- Long overdue cleanup of the way we handle relocation of our open
firmware trampoline (prom_init.c) on 64-bit by Anton Blanchard
- Support for saving/restoring & context switching the PPR (Processor
Priority Register) on server processors that support it. This
allows the kernel to preserve thread priorities established by
userspace. By Haren Myneni.
- DAWR (new watchpoint facility) support on Power8 by Michael Neuling
- Ability to change the DSCR (Data Stream Control Register) which
controls cache prefetching on a running process via ptrace by
Alexey Kardashevskiy
- Support for context switching the TAR register on Power8 (new
branch target register meant to be used by some new specific
userspace perf event interrupt facility which is yet to be enabled)
by Ian Munsie.
- Improve preservation of the CFAR register (which captures the
origin of a branch) on various exception conditions by Paulus.
- Move the Bestcomm DMA driver from arch powerpc to drivers/dma where
it belongs by Philippe De Muyter
- Support for Transactional Memory on Power8 by Michael Neuling
(based on original work by Matt Evans). For those curious about
the feature, the patch contains a pretty good description."
(See commit db8ff907027b: "powerpc: Documentation for transactional
memory on powerpc" for the mentioned description added to the file
Documentation/powerpc/transactional_memory.txt)
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (140 commits)
powerpc/kexec: Disable hard IRQ before kexec
powerpc/85xx: l2sram - Add compatible string for BSC9131 platform
powerpc/85xx: bsc9131 - Correct typo in SDHC device node
powerpc/e500/qemu-e500: enable coreint
powerpc/mpic: allow coreint to be determined by MPIC version
powerpc/fsl_pci: Store the pci ctlr device ptr in the pci ctlr struct
powerpc/85xx: Board support for ppa8548
powerpc/fsl: remove extraneous DIU platform functions
arch/powerpc/platforms/85xx/p1022_ds.c: adjust duplicate test
powerpc: Documentation for transactional memory on powerpc
powerpc: Add transactional memory to pseries and ppc64 defconfigs
powerpc: Add config option for transactional memory
powerpc: Add transactional memory to POWER8 cpu features
powerpc: Add new transactional memory state to the signal context
powerpc: Hook in new transactional memory code
powerpc: Routines for FP/VSX/VMX unavailable during a transaction
powerpc: Add transactional memory unavaliable execption handler
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes
powerpc: Add FP/VSX and VMX register load functions for transactional memory
powerpc: Add helper functions for transactional memory context switching
...
Commit a413f474a0 ("powerpc: Disable relocation on exceptions whenever
PR KVM is active") added calls to pSeries_disable_reloc_on_exc() and
pSeries_enable_reloc_on_exc() to book3s_pr.c, and added declarations
of those functions to <asm/hvcall.h>, but didn't add an include of
<asm/hvcall.h> to book3s_pr.c. 64-bit kernels seem to get hvcall.h
included via some other path, but 32-bit kernels fail to compile with:
arch/powerpc/kvm/book3s_pr.c: In function ‘kvmppc_core_init_vm’:
arch/powerpc/kvm/book3s_pr.c:1300:4: error: implicit declaration of function ‘pSeries_disable_reloc_on_exc’ [-Werror=implicit-function-declaration]
arch/powerpc/kvm/book3s_pr.c: In function ‘kvmppc_core_destroy_vm’:
arch/powerpc/kvm/book3s_pr.c:1316:4: error: implicit declaration of function ‘pSeries_enable_reloc_on_exc’ [-Werror=implicit-function-declaration]
cc1: all warnings being treated as errors
make[2]: *** [arch/powerpc/kvm/book3s_pr.o] Error 1
make[1]: *** [arch/powerpc/kvm] Error 2
make: *** [sub-make] Error 2
This fixes it by adding an include of hvcall.h.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The CFAR (Come-From Address Register) is a useful debugging aid that
exists on POWER7 processors. Currently HV KVM doesn't save or restore
the CFAR register for guest vcpus, making the CFAR of limited use in
guests.
This adds the necessary code to capture the CFAR value saved in the
early exception entry code (it has to be saved before any branch is
executed), save it in the vcpu.arch struct, and restore it on entry
to the guest.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When the guest triggers an alignment interrupt, we don't handle it properly
today and instead BUG_ON(). This really shouldn't happen.
Instead, we should just pass the interrupt back into the guest so it can deal
with it.
Reported-by: Gao Guanhua-B22826 <B22826@freescale.com>
Tested-by: Gao Guanhua-B22826 <B22826@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Current kvmppc_booke_handlers uses the same macro (KVM_HANDLER) and
all handlers are considered to be the same size. This will not be
the case if we want to use different macros for different handlers.
This patch improves the kvmppc_booke_handler so that it can
support different macros for different handlers.
Signed-off-by: Liu Yu <yu.liu@freescale.com>
[bharat.bhushan@freescale.com: Substantial changes]
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Like other places, use thread_struct to get vcpu reference.
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
The guest TLB handling code should not have any insight into how the host
TLB shadow code works.
kvmppc_e500_tlbil_all() is a function that is used for distinction between
e500v2 and e500mc (E.HV) on how to flush shadow entries. This function really
is private between the e500.c/e500mc.c file and e500_mmu_host.c.
Instead of this one, use the public kvmppc_core_flush_tlb() function to flush
all shadow TLB entries. As a nice side effect, with this we also end up
flushing TLB1 entries which we forgot to do before.
Signed-off-by: Alexander Graf <agraf@suse.de>
Host shadow TLB flushing is logic that the guest TLB code should have
no insight about. Declare the internal clear_tlb_refs and clear_tlb1_bitmap
functions static to the host TLB handling file.
Instead of these, we can use the already exported kvmppc_core_flush_tlb().
This gives us a common API across the board to say "please flush any
pending host shadow translation".
Signed-off-by: Alexander Graf <agraf@suse.de>
When a host mapping fault happens in a guest TLB1 entry today, we
map the translated guest entry into the host's TLB1.
This isn't particularly clever when the guest is mapped by normal 4k
pages, since these would be a lot better to put into TLB0 instead.
This patch adds the required logic to map 4k TLB1 shadow maps into
the host's TLB0.
Signed-off-by: Alexander Graf <agraf@suse.de>
This patch splits the file e500_tlb.c into e500_mmu.c (guest TLB handling)
and e500_mmu_host.c (host TLB handling).
The main benefit of this split is readability and maintainability. It's
just a lot harder to write dirty code :).
Signed-off-by: Alexander Graf <agraf@suse.de>
When emulating tlbwe, we want to automatically map the entry that just got
written in our shadow TLB map, because chances are quite high that it's
going to be used very soon.
Today this happens explicitly, duplicating all the logic that is in
kvmppc_mmu_map() already. Just call that one instead.
Signed-off-by: Alexander Graf <agraf@suse.de>
When shadow mapping a page, mapping this page can fail. In that case we
don't have a shadow map.
Take this case into account, otherwise we might end up writing bogus TLB
entries into the host TLB.
While at it, also move the write_stlbe() calls into the respective TLBn
handlers.
Signed-off-by: Alexander Graf <agraf@suse.de>
When we invalidate shadow TLB maps on the host, we don't mark them
as not valid. But we should.
Fix this by removing the E500_TLB_VALID from their flags when
invalidating.
Signed-off-by: Alexander Graf <agraf@suse.de>
Later patches want to call the function and it doesn't have
dependencies on anything below write_host_tlbe.
Move it higher up in the file.
Signed-off-by: Alexander Graf <agraf@suse.de>
The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.
CC: Alexander Graf <agraf@suse.de>
CC: Avi Kivity <avi@redhat.com>
CC: Marcelo Tosatti <mtosatti@redhat.com>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Guests can trigger MMIO exits using dcbf. Since we don't emulate cache
incoherent MMIO, just do nothing and move on.
Reported-by: Ben Collins <ben.c@servergy.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Tested-by: Ben Collins <ben.c@servergy.com>
CC: stable@vger.kernel.org
We need to be able to read and write the contents of the EPR register
from user space.
This patch implements that logic through the ONE_REG API and declares
its (never implemented) SREGS counterpart as deprecated.
Signed-off-by: Alexander Graf <agraf@suse.de>
The External Proxy Facility in FSL BookE chips allows the interrupt
controller to automatically acknowledge an interrupt as soon as a
core gets its pending external interrupt delivered.
Today, user space implements the interrupt controller, so we need to
check on it during such a cycle.
This patch implements logic for user space to enable EPR exiting,
disable EPR exiting and EPR exiting itself, so that user space can
acknowledge an interrupt when an external interrupt has successfully
been delivered into the guest vcpu.
Signed-off-by: Alexander Graf <agraf@suse.de>
The EPR register is potentially valid for PR KVM as well, so we need
to emulate accesses to it. It's only defined for reading, so only
handle the mfspr case.
Signed-off-by: Alexander Graf <agraf@suse.de>
When injecting an interrupt into guest context, we usually don't need
to check for requests anymore. At least not until today.
With the introduction of EPR, we will have to create a request when the
guest has successfully accepted an external interrupt though.
So we need to prepare the interrupt delivery to abort guest entry
gracefully. Otherwise we'd delay the EPR request.
Signed-off-by: Alexander Graf <agraf@suse.de>
On mfspr/mtspr emulation path Book3E's MMUCFG SPR with value 1015 clashes
with G4's MSSSR0 SPR. Move MSSSR0 emulation from generic part to Books3S.
MSSSR0 also clashes with Book3S's DABRX SPR. DABRX was not explicitly
handled so Book3S execution flow will behave as before.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
When running on top of pHyp, the hypercall instruction "sc 1" goes
straight into pHyp without trapping in supervisor mode.
So if we want to support PAPR guest in this configuration we need to
add a second way of accessing PAPR hypercalls, preferably with the
exact same semantics except for the instruction.
So let's overlay an officially reserved instruction and emulate PAPR
hypercalls whenever we hit that one.
Signed-off-by: Alexander Graf <agraf@suse.de>
When we hit an emulation result that we didn't expect, that is an error,
but it's nothing that warrants a BUG(), because it can be guest triggered.
So instead, let's only WARN() the user that this happened.
Signed-off-by: Alexander Graf <agraf@suse.de>
For PR KVM we allow userspace to map 0xc000000000000000. Because
transitioning from userspace to the guest kernel may use the relocated
exception vectors we have to disable relocation on exceptions whenever
PR KVM is active as we cannot trust that address.
This issue does not apply to HV KVM, since changing from a guest to the
hypervisor will never use the relocated exception vectors.
Currently the hypervisor interface only allows us to toggle relocation
on exceptions on a partition wide scope, so we need to globally disable
relocation on exceptions when the first PR KVM instance is started and
only re-enable them when all PR KVM instances have been destroyed.
It's a bit heavy handed, but until the hypervisor gives us a lightweight
way to toggle relocation on exceptions on a single thread it's only real
option.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Fixes this build breakage:
arch/powerpc/kvm/book3s_hv_ras.c: In function ‘kvmppc_realmode_mc_power7’:
arch/powerpc/kvm/book3s_hv_ras.c:126:23: error: ‘struct paca_struct’ has no member named ‘opal_mc_evt’
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
There's no need for this to be an int, it holds a boolean.
Move to the end of the struct for alignment.
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
It's easy to confuse KVM_MEMORY_SLOTS and KVM_MEM_SLOTS_NUM. One is
the user accessible slots and the other is user + private. Make this
more obvious.
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Implement ONE_REG interface for EPCR register adding KVM_REG_PPC_EPCR to
the list of ONE_REG PPC supported registers.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
[agraf: remove HV dependency, use get/put_user]
Signed-off-by: Alexander Graf <agraf@suse.de>
Add EPCR support in booke mtspr/mfspr emulation. EPCR register is defined only
for 64-bit and HV categories, we will expose it at this point only to 64-bit
virtual processors running on 64-bit HV hosts.
Define a reusable setter function for vcpu's EPCR.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
[agraf: move HV dependency in the code]
Signed-off-by: Alexander Graf <agraf@suse.de>
When delivering guest IRQs, update MSR computation mode according to guest
interrupt computation mode found in EPCR.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
[agraf: remove HV dependency in the code]
Signed-off-by: Alexander Graf <agraf@suse.de>
Extend MAS2 EPN mask to retain most significant bits on 64-bit hosts.
Use this mask in tlb effective address accessor.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Mask high 32 bits of MAS2's effective page number in tlbwe emulation for guests
running in 32-bit mode.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Add emulation helper for getting instruction ea and refactor tlb instruction
emulation to use it.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
[agraf: keep rt variable around]
Signed-off-by: Alexander Graf <agraf@suse.de>
Add interrupt handling support for 64-bit bookehv hosts. Unify 32 and 64 bit
implementations using a common stack layout and a common execution flow starting
from kvm_handler_common macro. Update documentation for 64-bit input register
values. This patch only address the bolted TLB miss exception handlers version.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
GET_VCPU define will not be implemented for 64-bit for performance reasons
so get rid of it also on 32-bit.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
64-bit GCC 4.5.1 warns about an uninitialized variable which was guarded
by a flag. Initialize the variable to make it happy.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
[agraf: reword comment]
Signed-off-by: Alexander Graf <agraf@suse.de>
Currently, if a machine check interrupt happens while we are in the
guest, we exit the guest and call the host's machine check handler,
which tends to cause the host to panic. Some machine checks can be
triggered by the guest; for example, if the guest creates two entries
in the SLB that map the same effective address, and then accesses that
effective address, the CPU will take a machine check interrupt.
To handle this better, when a machine check happens inside the guest,
we call a new function, kvmppc_realmode_machine_check(), while still in
real mode before exiting the guest. On POWER7, it handles the cases
that the guest can trigger, either by flushing and reloading the SLB,
or by flushing the TLB, and then it delivers the machine check interrupt
directly to the guest without going back to the host. On POWER7, the
OPAL firmware patches the machine check interrupt vector so that it
gets control first, and it leaves behind its analysis of the situation
in a structure pointed to by the opal_mc_evt field of the paca. The
kvmppc_realmode_machine_check() function looks at this, and if OPAL
reports that there was no error, or that it has handled the error, we
also go straight back to the guest with a machine check. We have to
deliver a machine check to the guest since the machine check interrupt
might have trashed valid values in SRR0/1.
If the machine check is one we can't handle in real mode, and one that
OPAL hasn't already handled, or on PPC970, we exit the guest and call
the host's machine check handler. We do this by jumping to the
machine_check_fwnmi label, rather than absolute address 0x200, because
we don't want to re-execute OPAL's handler on POWER7. On PPC970, the
two are equivalent because address 0x200 just contains a branch.
Then, if the host machine check handler decides that the system can
continue executing, kvmppc_handle_exit() delivers a machine check
interrupt to the guest -- once again to let the guest know that SRR0/1
have been modified.
Signed-off-by: Paul Mackerras <paulus@samba.org>
[agraf: fix checkpatch warnings]
Signed-off-by: Alexander Graf <agraf@suse.de>
When we change or remove a HPT (hashed page table) entry, we can do
either a global TLB invalidation (tlbie) that works across the whole
machine, or a local invalidation (tlbiel) that only affects this core.
Currently we do local invalidations if the VM has only one vcpu or if
the guest requests it with the H_LOCAL flag, though the guest Linux
kernel currently doesn't ever use H_LOCAL. Then, to cope with the
possibility that vcpus moving around to different physical cores might
expose stale TLB entries, there is some code in kvmppc_hv_entry to
flush the whole TLB of entries for this VM if either this vcpu is now
running on a different physical core from where it last ran, or if this
physical core last ran a different vcpu.
There are a number of problems on POWER7 with this as it stands:
- The TLB invalidation is done per thread, whereas it only needs to be
done per core, since the TLB is shared between the threads.
- With the possibility of the host paging out guest pages, the use of
H_LOCAL by an SMP guest is dangerous since the guest could possibly
retain and use a stale TLB entry pointing to a page that had been
removed from the guest.
- The TLB invalidations that we do when a vcpu moves from one physical
core to another are unnecessary in the case of an SMP guest that isn't
using H_LOCAL.
- The optimization of using local invalidations rather than global should
apply to guests with one virtual core, not just one vcpu.
(None of this applies on PPC970, since there we always have to
invalidate the whole TLB when entering and leaving the guest, and we
can't support paging out guest memory.)
To fix these problems and simplify the code, we now maintain a simple
cpumask of which cpus need to flush the TLB on entry to the guest.
(This is indexed by cpu, though we only ever use the bits for thread
0 of each core.) Whenever we do a local TLB invalidation, we set the
bits for every cpu except the bit for thread 0 of the core that we're
currently running on. Whenever we enter a guest, we test and clear the
bit for our core, and flush the TLB if it was set.
On initial startup of the VM, and when resetting the HPT, we set all the
bits in the need_tlb_flush cpumask, since any core could potentially have
stale TLB entries from the previous VM to use the same LPID, or the
previous contents of the HPT.
Then, we maintain a count of the number of online virtual cores, and use
that when deciding whether to use a local invalidation rather than the
number of online vcpus. The code to make that decision is extracted out
into a new function, global_invalidates(). For multi-core guests on
POWER7 (i.e. when we are using mmu notifiers), we now never do local
invalidations regardless of the H_LOCAL flag.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Linus Torvalds
Scott Wood
Zhang Yanfei
Aneesh Kumar K.V
Sasha Levin
Paul Mackerras
Alexander Graf
Bharat Bhushan
Benjamin Herrenschmidt
Greg Kroah-Hartman
Kees Cook
Mihai Caraman
Ian Munsie
Andreas Schwab
Alex Williamson