It is better to get all loads for the register values in flight
before starting to switch LPID, PID, and LPCR because those
mtSPRs are expensive and serialising.
This also just tidies up the code for a potential future change
to the context switching sequence.
Signed-off-by: Nicholas Piggin
---
Maybe cite the correct parts of the patch where my questions arose for context.
---
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index a94b0cd0bdc5ca..4ffd6791b03ec0 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -1465,7 +1465,7 @@ int
This removes the fixed-size lpid_inuse array.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/powerpc.c | 25 +
1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 102993462872..c527a5751b46
This removes the fixed sized kvm->arch.nested_guests array.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/include/asm/kvm_host.h | 3 +-
arch/powerpc/kvm/book3s_hv_nested.c | 110 +++-
2 files changed, 59 insertions(+), 54 deletions(-)
diff --git
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA256
Hi Linus,
Please pull powerpc fixes for 5.17.
There's a change to kernel/bpf and one in tools/bpf, both have Daniel's ack.
cheers
The following changes since commit 29ec39fcf11e4583eb8d5174f756ea109c77cc44:
Merge tag 'powerpc-5.17-1' of
Rather than tie this to KVMPPC_NR_LPIDS which is becoming more dynamic,
fix it to 4096 (12-bits) explicitly for now.
kvmhv_get_nested() does not have to check against KVM_MAX_NESTED_GUESTS
because the L1 partition table registration hcall already did that, and
it checks against the partition
KVMPPC_NR_LPIDS no longer represents any size restriction on the
LPID space and can be removed. A CPU with more than 12 LPID bits
implemented will now be able to create more than 4095 guests.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/include/asm/kvm_book3s_asm.h | 3 ---
As some have probably noticed, we are seeing errors like ' Error:
unrecognized opcode: `ptesync'' 'dssall' and 'stbcix' as a result of
binutils changes, making compiling all that more fun again. The only
question on my mind still is this:
diff --git a/arch/powerpc/include/asm/io.h
Removing kvmppc_claim_lpid makes the lpid allocator API a bit simpler to
change the underlying implementation in a future patch.
The host LPID is always 0, so that can be a detail of the allocator. If
the allocator range is restricted, that can reserve LPIDs at the top of
the range. This allows
The LPID allocator init is changed to:
- use mmu_lpid_bits rather than hard-coding;
- use KVM_MAX_NESTED_GUESTS for nested hypervisors;
- not reserve the top LPID on POWER9 and newer CPUs.
The reserved LPID is made a POWER7/8-specific detail.
Signed-off-by: Nicholas Piggin
---
With LPID width plumbed through from firmware, LPID allocations can now
be dynamic, which requires changing the fixed sized bitmap. Rather than
just dynamically sizing it, switch to IDA allocator.
Nested KVM stays with a fixed 12-bit LPID width for now, but it is also
moved to a more dynamic
Hari Bathini writes:
> With commit a4e92ce8e4c8 ("powerpc/fadump: Reservationless firmware
> assisted dump"), Linux kernel's Contiguous Memory Allocator (CMA)
> based reservation was introduced in fadump. That change was aimed at
> using CMA to let applications utilize the memory reserved for
Hi Greg,
> Ok, this is like the 3rd or 4th different platform-specific proposal for
> this type of functionality. I think we need to give up on
> platform-specific user/kernel apis on this (random sysfs/securityfs
> files scattered around the tree), and come up with a standard place for
> all of
The pull request you sent on Sun, 23 Jan 2022 22:19:16 +1100:
> https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git
> tags/powerpc-5.17-2
has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/dd81e1c7d5fb126e5fbc5c9e334d7b3ec29a16a0
Thank you!
--
PowerPC code uses cpumask_weight() to compare the weight of cpumask
with a given number. We can do it more efficiently with
cpumask_weight_{eq, ...} because conditional cpumask_weight may stop
traversing the cpumask earlier, as soon as condition is met.
Signed-off-by: Yury Norov
---
qman_test_stash() calls cpumask_weight() to compare the weight of
cpumask with a given number. We can do it more efficiently with
cpumask_weight_lt because conditional cpumask_weight may stop
traversing the cpumask earlier, as soon as condition is met.
Signed-off-by: Yury Norov
---
Now I remembered reading something from 2013 on 'lwsync',
https://gcc.gnu.org/legacy-ml/gcc-patches/2006-11/msg01238.html
https://gcc.gnu.org/legacy-ml/gcc-patches/2012-07/msg01062.html
so that would end up something like
---
Le 24/01/2022 à 06:57, Nicholas Piggin a écrit :
> As discussed previously
>
> https://lists.ozlabs.org/pipermail/linuxppc-dev/2022-January/238946.html
>
> I'm wondering whether PPC32 should be returning -1 for syscall
> instructions too here? That could be done in another patch anyway.
>
Hi Andrew,
Could you please pick these patches via -mm tree.
On 17/01/22 1:22 pm, Hari Bathini wrote:
Commit 072355c1cf2d ("mm/cma: expose all pages to the buddy if
activation of an area fails") started exposing all pages to buddy
allocator on CMA activation failure. But there can be CMA
As discussed previously
https://lists.ozlabs.org/pipermail/linuxppc-dev/2022-January/238946.html
I'm wondering whether PPC32 should be returning -1 for syscall
instructions too here? That could be done in another patch anyway.
Thanks,
Nick
Nicholas Piggin (2):
powerpc/64: remove system call
Per the ISA, a Trace interrupt is not generated for a system call
[vectored] instruction. Reject uprobes on such instructions as we are
not emulating a system call [vectored] instruction anymore.
Signed-off-by: Naveen N. Rao
[np: Switch to pr_info_ratelimited]
Signed-off-by: Nicholas Piggin
---
emulate_step instruction emulation including sc instruction emulation
initially appeared in xmon. It then emulation code was then moved into
sstep.c where kprobes could use it too, and later hw_breakpoint and
uprobes started to use it.
Until uprobes, the only instruction emulation users were for
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