* Re: [v3 1/5] KVM: PPC: Book3S HV: Disable page merging in H_SVM_INIT_START
From: Bharata B Rao @ 2020-07-13 5:29 UTC (permalink / raw)
To: Ram Pai
Cc: ldufour, cclaudio, kvm-ppc, sathnaga, aneesh.kumar, sukadev,
linuxppc-dev, bauerman, david
In-Reply-To: <1594458827-31866-2-git-send-email-linuxram@us.ibm.com>
On Sat, Jul 11, 2020 at 02:13:43AM -0700, Ram Pai wrote:
> Merging of pages associated with each memslot of a SVM is
> disabled the page is migrated in H_SVM_PAGE_IN handler.
>
> This operation should have been done much earlier; the moment the VM
> is initiated for secure-transition. Delaying this operation, increases
> the probability for those pages to acquire new references , making it
> impossible to migrate those pages in H_SVM_PAGE_IN handler.
>
> Disable page-migration in H_SVM_INIT_START handling.
While it is a good idea to disable KSM merging for all VMAs during
H_SVM_INIT_START, I am curious if you did observe an actual case of
ksm_madvise() failing which resulted in subsequent H_SVM_PAGE_IN
failing to migrate?
>
> Signed-off-by: Ram Pai <linuxram@us.ibm.com>
> ---
> arch/powerpc/kvm/book3s_hv_uvmem.c | 96 +++++++++++++++++++++++++++++---------
> 1 file changed, 74 insertions(+), 22 deletions(-)
>
> diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
> index 3d987b1..bfc3841 100644
> --- a/arch/powerpc/kvm/book3s_hv_uvmem.c
> +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
> @@ -211,6 +211,65 @@ static bool kvmppc_gfn_is_uvmem_pfn(unsigned long gfn, struct kvm *kvm,
> return false;
> }
>
> +static int kvmppc_memslot_page_merge(struct kvm *kvm,
> + struct kvm_memory_slot *memslot, bool merge)
> +{
> + unsigned long gfn = memslot->base_gfn;
> + unsigned long end, start = gfn_to_hva(kvm, gfn);
> + int ret = 0;
> + struct vm_area_struct *vma;
> + int merge_flag = (merge) ? MADV_MERGEABLE : MADV_UNMERGEABLE;
> +
> + if (kvm_is_error_hva(start))
> + return H_STATE;
This and other cases below seem to be a new return value from
H_SVM_INIT_START. May be update the documentation too along with
this patch?
> +
> + end = start + (memslot->npages << PAGE_SHIFT);
> +
> + down_write(&kvm->mm->mmap_sem);
When you rebase the patches against latest upstream you may want to
replace the above and other instances by mmap_write/read_lock().
> + do {
> + vma = find_vma_intersection(kvm->mm, start, end);
> + if (!vma) {
> + ret = H_STATE;
> + break;
> + }
> + ret = ksm_madvise(vma, vma->vm_start, vma->vm_end,
> + merge_flag, &vma->vm_flags);
> + if (ret) {
> + ret = H_STATE;
> + break;
> + }
> + start = vma->vm_end + 1;
> + } while (end > vma->vm_end);
> +
> + up_write(&kvm->mm->mmap_sem);
> + return ret;
> +}
> +
> +static int __kvmppc_page_merge(struct kvm *kvm, bool merge)
> +{
> + struct kvm_memslots *slots;
> + struct kvm_memory_slot *memslot;
> + int ret = 0;
> +
> + slots = kvm_memslots(kvm);
> + kvm_for_each_memslot(memslot, slots) {
> + ret = kvmppc_memslot_page_merge(kvm, memslot, merge);
> + if (ret)
> + break;
> + }
> + return ret;
> +}
> +
> +static inline int kvmppc_disable_page_merge(struct kvm *kvm)
> +{
> + return __kvmppc_page_merge(kvm, false);
> +}
> +
> +static inline int kvmppc_enable_page_merge(struct kvm *kvm)
> +{
> + return __kvmppc_page_merge(kvm, true);
> +}
> +
> unsigned long kvmppc_h_svm_init_start(struct kvm *kvm)
> {
> struct kvm_memslots *slots;
> @@ -232,11 +291,18 @@ unsigned long kvmppc_h_svm_init_start(struct kvm *kvm)
> return H_AUTHORITY;
>
> srcu_idx = srcu_read_lock(&kvm->srcu);
> +
> + /* disable page-merging for all memslot */
> + ret = kvmppc_disable_page_merge(kvm);
> + if (ret)
> + goto out;
> +
> + /* register the memslot */
> slots = kvm_memslots(kvm);
> kvm_for_each_memslot(memslot, slots) {
> if (kvmppc_uvmem_slot_init(kvm, memslot)) {
> ret = H_PARAMETER;
> - goto out;
> + break;
> }
> ret = uv_register_mem_slot(kvm->arch.lpid,
> memslot->base_gfn << PAGE_SHIFT,
> @@ -245,9 +311,12 @@ unsigned long kvmppc_h_svm_init_start(struct kvm *kvm)
> if (ret < 0) {
> kvmppc_uvmem_slot_free(kvm, memslot);
> ret = H_PARAMETER;
> - goto out;
> + break;
> }
> }
> +
> + if (ret)
> + kvmppc_enable_page_merge(kvm);
Is there any use of enabling KSM merging in the failure path here?
Won't UV terminate the VM if H_SVM_INIT_START fails? If there is no need,
you can do away with some extra routines above.
> out:
> srcu_read_unlock(&kvm->srcu, srcu_idx);
> return ret;
> @@ -384,7 +453,7 @@ static struct page *kvmppc_uvmem_get_page(unsigned long gpa, struct kvm *kvm)
> */
> static int kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start,
> unsigned long end, unsigned long gpa, struct kvm *kvm,
> - unsigned long page_shift, bool *downgrade)
> + unsigned long page_shift)
> {
> unsigned long src_pfn, dst_pfn = 0;
> struct migrate_vma mig;
> @@ -400,18 +469,6 @@ static int kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start,
> mig.src = &src_pfn;
> mig.dst = &dst_pfn;
>
> - /*
> - * We come here with mmap_sem write lock held just for
> - * ksm_madvise(), otherwise we only need read mmap_sem.
> - * Hence downgrade to read lock once ksm_madvise() is done.
> - */
> - ret = ksm_madvise(vma, vma->vm_start, vma->vm_end,
> - MADV_UNMERGEABLE, &vma->vm_flags);
I haven't seen the subsequent patches yet, but guess you are
taking care of disabling KSM mering for hot-plugged memory too.
Regards,
Bharata.
^ permalink raw reply
* Re: [PATCH v2 0/3] Power10 basic energy management
From: Nicholas Piggin @ 2020-07-13 5:23 UTC (permalink / raw)
To: benh, ego, linux-kernel, linuxppc-dev, mikey, mpe, paulus,
pratik.r.sampat, Pratik Rajesh Sampat, ravi.bangoria, svaidy
In-Reply-To: <20200710052207.12003-1-psampat@linux.ibm.com>
Excerpts from Pratik Rajesh Sampat's message of July 10, 2020 3:22 pm:
> Changelog v1 --> v2:
> 1. Save-restore DAWR and DAWRX unconditionally as they are lost in
> shallow idle states too
> 2. Rename pnv_first_spr_loss_level to pnv_first_fullstate_loss_level to
> correct naming terminology
>
> Pratik Rajesh Sampat (3):
> powerpc/powernv/idle: Exclude mfspr on HID1,4,5 on P9 and above
> powerpc/powernv/idle: save-restore DAWR0,DAWRX0 for P10
> powerpc/powernv/idle: Rename pnv_first_spr_loss_level variable
>
> arch/powerpc/platforms/powernv/idle.c | 34 +++++++++++++++++----------
> 1 file changed, 22 insertions(+), 12 deletions(-)
These look okay to me, but the CPU_FTR_ARCH_300 test for
pnv_power9_idle_init() is actually wrong, it should be a PVR test
because idle is not completely architected (not even shallow stop
states, unfortunately).
It doesn't look like we support POWER10 idle correctly yet, and on older
kernels it wouldn't work even if we fixed newer, so ideally the PVR
check would be backported as a fix in the front of the series.
Sadly, we have no OPAL idle driver yet. Hopefully we will before the
next processor shows up :P
Thanks,
Nick
^ permalink raw reply
* Re: [PATCH 4/5] dma-mapping: add a dma_ops_bypass flag to struct device
From: Alexey Kardashevskiy @ 2020-07-13 4:59 UTC (permalink / raw)
To: Christoph Hellwig, iommu
Cc: Björn Töpel, Daniel Borkmann, Greg Kroah-Hartman,
Joerg Roedel, Robin Murphy, linux-kernel, Jesper Dangaard Brouer,
linuxppc-dev, Lu Baolu
In-Reply-To: <20200708152449.316476-5-hch@lst.de>
On 09/07/2020 01:24, Christoph Hellwig wrote:
> Several IOMMU drivers have a bypass mode where they can use a direct
> mapping if the devices DMA mask is large enough. Add generic support
> to the core dma-mapping code to do that to switch those drivers to
> a common solution.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> include/linux/device.h | 8 +++++
> kernel/dma/Kconfig | 8 +++++
> kernel/dma/mapping.c | 74 +++++++++++++++++++++++++++++-------------
> 3 files changed, 68 insertions(+), 22 deletions(-)
>
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 4c4af98321ebd6..1f71acf37f78d7 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -523,6 +523,11 @@ struct dev_links_info {
> * sync_state() callback.
> * @dma_coherent: this particular device is dma coherent, even if the
> * architecture supports non-coherent devices.
> + * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the
> + * streaming DMA operations (->map_* / ->unmap_* / ->sync_*),
> + * and optionall (if the coherent mask is large enough) also
s/optionall/optional/g
Otherwise the series looks good and works well on powernv and pseries.
Thanks,
--
Alexey
^ permalink raw reply
* Re: [RFC PATCH 7/7] lazy tlb: shoot lazies, a non-refcounting lazy tlb option
From: Nicholas Piggin @ 2020-07-13 4:58 UTC (permalink / raw)
To: Peter Zijlstra
Cc: linux-arch, Arnd Bergmann, x86, linux-kernel, linux-mm,
Mathieu Desnoyers, linuxppc-dev
In-Reply-To: <20200710093556.GY4800@hirez.programming.kicks-ass.net>
Excerpts from Peter Zijlstra's message of July 10, 2020 7:35 pm:
> On Fri, Jul 10, 2020 at 11:56:46AM +1000, Nicholas Piggin wrote:
>> On big systems, the mm refcount can become highly contented when doing
>> a lot of context switching with threaded applications (particularly
>> switching between the idle thread and an application thread).
>>
>> Abandoning lazy tlb slows switching down quite a bit in the important
>> user->idle->user cases, so so instead implement a non-refcounted scheme
>> that causes __mmdrop() to IPI all CPUs in the mm_cpumask and shoot down
>> any remaining lazy ones.
>>
>> On a 16-socket 192-core POWER8 system, a context switching benchmark
>> with as many software threads as CPUs (so each switch will go in and
>> out of idle), upstream can achieve a rate of about 1 million context
>> switches per second. After this patch it goes up to 118 million.
>
> That's mighty impressive, however:
Well, it's the usual case of "find a bouncing line and scale up the
machine size until you achieve your desired improvements" :) But we
are looking at some fundamental scalabilities and seeing if we can
improve a few things.
>
>> +static void shoot_lazy_tlbs(struct mm_struct *mm)
>> +{
>> + if (IS_ENABLED(CONFIG_MMU_LAZY_TLB_SHOOTDOWN)) {
>> + smp_call_function_many(mm_cpumask(mm), do_shoot_lazy_tlb, (void *)mm, 1);
>> + do_shoot_lazy_tlb(mm);
>> + }
>> +}
>
> IIRC you (power) never clear a CPU from that mask, so for other
> workloads I can see this resulting in massive amounts of IPIs.
>
> For instance, take as many processes as you have CPUs. For each,
> manually walk the task across all CPUs and exit. Again.
>
> Clearly, that's an extreme, but still...
We do have some issues with that, it does tend to be very self-limiting
though, short lived tasks that can drive lots of exits won't get to run
on a lot of cores.
It's worth keeping an eye on, it may not be too hard to mitigate the IPIs
doing something dumb like collecting a queue of mms before killing a
batch of them.
Thanks,
Nick
^ permalink raw reply
* Re: [RFC PATCH 4/7] x86: use exit_lazy_tlb rather than membarrier_mm_sync_core_before_usermode
From: Nicholas Piggin @ 2020-07-13 4:45 UTC (permalink / raw)
To: Andy Lutomirski
Cc: linux-arch, Arnd Bergmann, Peter Zijlstra, X86 ML, LKML, Linux-MM,
Mathieu Desnoyers, linuxppc-dev
In-Reply-To: <CALCETrVqHDLo09HcaoeOoAVK8w+cNWkSNTLkDDU=evUhaXkyhQ@mail.gmail.com>
Excerpts from Andy Lutomirski's message of July 11, 2020 3:04 am:
> On Thu, Jul 9, 2020 at 6:57 PM Nicholas Piggin <npiggin@gmail.com> wrote:
>>
>> And get rid of the generic sync_core_before_usermode facility.
>>
>> This helper is the wrong way around I think. The idea that membarrier
>> state requires a core sync before returning to user is the easy one
>> that does not need hiding behind membarrier calls. The gap in core
>> synchronization due to x86's sysret/sysexit and lazy tlb mode, is the
>> tricky detail that is better put in x86 lazy tlb code.
>>
>> Consider if an arch did not synchronize core in switch_mm either, then
>> membarrier_mm_sync_core_before_usermode would be in the wrong place
>> but arch specific mmu context functions would still be the right place.
>> There is also a exit_lazy_tlb case that is not covered by this call, which
>> could be a bugs (kthread use mm the membarrier process's mm then context
>> switch back to the process without switching mm or lazy mm switch).
>>
>> This makes lazy tlb code a bit more modular.
>
> The mm-switching and TLB-management has often had the regrettable
> property that it gets wired up in a way that seems to work at the time
> but doesn't have clear semantics, and I'm a bit concerned that this
> patch is in that category.
It's much more explicit in the core code about where hooks are called
after this patch. And then the x86 membarrier implementation details
are contained to the x86 code where they belong, and we don't have the
previous hook with unclear semantics missing from core code.
> If I'm understanding right, you're trying
> to enforce the property that exiting lazy TLB mode will promise to
> sync the core eventually. But this has all kinds of odd properties:
>
> - Why is exit_lazy_tlb() getting called at all in the relevant cases?
It's a property of how MEMBARRIER_SYNC_CORE is implemented by arch/x86,
see the membarrier comment in finish_task_switch (for analogous reason).
> When is it permissible to call it?
Comment for the asm-generic code says it's to be called when the lazy
active mm becomes non-lazy.
> I look at your new code and see:
>
>> +/*
>> + * Ensure that a core serializing instruction is issued before returning
>> + * to user-mode, if a SYNC_CORE was requested. x86 implements return to
>> + * user-space through sysexit, sysrel, and sysretq, which are not core
>> + * serializing.
>> + *
>> + * See the membarrier comment in finish_task_switch as to why this is done
>> + * in exit_lazy_tlb.
>> + */
>> +#define exit_lazy_tlb exit_lazy_tlb
>> +static inline void exit_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
>> +{
>> + /* Switching mm is serializing with write_cr3 */
>> + if (tsk->mm != mm)
>> + return;
>
> And my brain says WTF? Surely you meant something like if
> (WARN_ON_ONCE(tsk->mm != mm)) { /* egads, what even happened? how do
> we try to recover well enough to get a crashed logged at least? */ }
No, the active mm can be unlazied by switching to a different mm.
> So this needs actual documentation, preferably in comments near the
> function, of what the preconditions are and what this mm parameter is.
> Once that's done, then we could consider whether it's appropriate to
> have this function promise to sync the core under some conditions.
It's documented in generic code. I prefer not to duplicate comments
too much but I can add a "refer to asm-generic version for usage" or
something if you'd like?
> - This whole structure seems to rely on the idea that switching mm
> syncs something.
Which whole structure? The x86 implementation of sync core explicitly
does rely on that, yes. But I've pulled that out of core code with
this patch.
> I periodically ask chip vendor for non-serializing
> mm switches. Specifically, in my dream world, we have totally
> separate user and kernel page tables. Changing out the user tables
> doesn't serialize or even create a fence. Instead it creates the
> minimum required pipeline hazard such that user memory access and
> switches to usermode will make sure they access memory through the
> correct page tables. I haven't convinced a chip vendor yet, but there
> are quite a few hundreds of cycles to be saved here.
The fundmaental difficulty is that the kernel can still access user
mappings any time after the switch. We can probably handwave ways
around it by serializing lazily when encountering the next user
access and hoping that most of your mm switches result in a kernel
exit that serializes or some other unavoidable serialize so you can
avoid the mm switch one. In practice it sounds like a lot of trouble.
But anyway the sync core could presumably be adjusted or reasoned to
still be correct, depending on how it works.
> With this in
> mind, I see the fencing aspects of the TLB handling code as somewhat
> of an accident. I'm fine with documenting them and using them to
> optimize other paths, but I think it should be explicit. For example:
>
> /* Also does a full barrier? (Or a sync_core()-style barrier.)
> However, if you rely on this, you must document it in a comment where
> you call this function. *?
> void switch_mm_irqs_off()
> {
> }
>
> This is kind of like how we strongly encourage anyone using smp_?mb()
> to document what they are fencing against.
Hmm. I don't think anything outside core scheduler/arch code is allowed
to assume that, because they don't really know if schedule() will cause
a switch. Hopefully nobody does, I would agree it shouldn't be
encouraged.
It is pretty fundamental to how we do task CPU migration so I don't see
it ever going away. A push model where the source CPU has to release
tasks that it last ran before they can be run elsewhere is unworkable.
(Or maybe it's not, but no getting around that would require careful
audits of said low level code).
> Also, as it stands, I can easily see in_irq() ceasing to promise to
> serialize. There are older kernels for which it does not promise to
> serialize. And I have plans to make it stop serializing in the
> nearish future.
You mean x86's return from interrupt? Sounds fun... you'll konw where to
update the membarrier sync code, at least :)
Thanks,
Nick
^ permalink raw reply
* [PATCH V5 4/4] Documentation/mm: Add descriptions for arch page table helpers
From: Anshuman Khandual @ 2020-07-13 3:23 UTC (permalink / raw)
To: linux-mm
Cc: linux-doc, Catalin Marinas, Heiko Carstens, Paul Mackerras,
H. Peter Anvin, agordeev, Will Deacon, linux-riscv, linux-arch,
linux-s390, Jonathan Corbet, x86, Mike Rapoport,
Christian Borntraeger, Ingo Molnar, linux-arm-kernel, ziy,
linux-snps-arc, Vasily Gorbik, Anshuman Khandual, cai,
Paul Walmsley, Kirill A . Shutemov, Thomas Gleixner,
gerald.schaefer, christophe.leroy, Vineet Gupta, linux-kernel,
Palmer Dabbelt, aneesh.kumar, Borislav Petkov, Andrew Morton,
linuxppc-dev, rppt
In-Reply-To: <1594610587-4172-1-git-send-email-anshuman.khandual@arm.com>
This adds a specific description file for all arch page table helpers which
is in sync with the semantics being tested via CONFIG_DEBUG_VM_PGTABLE. All
future changes either to these descriptions here or the debug test should
always remain in sync.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-riscv@lists.infradead.org
Cc: x86@kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Suggested-by: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
Documentation/vm/arch_pgtable_helpers.rst | 258 ++++++++++++++++++++++
mm/debug_vm_pgtable.c | 6 +
2 files changed, 264 insertions(+)
create mode 100644 Documentation/vm/arch_pgtable_helpers.rst
diff --git a/Documentation/vm/arch_pgtable_helpers.rst b/Documentation/vm/arch_pgtable_helpers.rst
new file mode 100644
index 000000000000..f3591ee3aaa8
--- /dev/null
+++ b/Documentation/vm/arch_pgtable_helpers.rst
@@ -0,0 +1,258 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+.. _arch_page_table_helpers:
+
+===============================
+Architecture Page Table Helpers
+===============================
+
+Generic MM expects architectures (with MMU) to provide helpers to create, access
+and modify page table entries at various level for different memory functions.
+These page table helpers need to conform to a common semantics across platforms.
+Following tables describe the expected semantics which can also be tested during
+boot via CONFIG_DEBUG_VM_PGTABLE option. All future changes in here or the debug
+test need to be in sync.
+
+======================
+PTE Page Table Helpers
+======================
+
++---------------------------+--------------------------------------------------+
+| pte_same | Tests whether both PTE entries are the same |
++---------------------------+--------------------------------------------------+
+| pte_bad | Tests a non-table mapped PTE |
++---------------------------+--------------------------------------------------+
+| pte_present | Tests a valid mapped PTE |
++---------------------------+--------------------------------------------------+
+| pte_young | Tests a young PTE |
++---------------------------+--------------------------------------------------+
+| pte_dirty | Tests a dirty PTE |
++---------------------------+--------------------------------------------------+
+| pte_write | Tests a writable PTE |
++---------------------------+--------------------------------------------------+
+| pte_special | Tests a special PTE |
++---------------------------+--------------------------------------------------+
+| pte_protnone | Tests a PROT_NONE PTE |
++---------------------------+--------------------------------------------------+
+| pte_devmap | Tests a ZONE_DEVICE mapped PTE |
++---------------------------+--------------------------------------------------+
+| pte_soft_dirty | Tests a soft dirty PTE |
++---------------------------+--------------------------------------------------+
+| pte_swp_soft_dirty | Tests a soft dirty swapped PTE |
++---------------------------+--------------------------------------------------+
+| pte_mkyoung | Creates a young PTE |
++---------------------------+--------------------------------------------------+
+| pte_mkold | Creates an old PTE |
++---------------------------+--------------------------------------------------+
+| pte_mkdirty | Creates a dirty PTE |
++---------------------------+--------------------------------------------------+
+| pte_mkclean | Creates a clean PTE |
++---------------------------+--------------------------------------------------+
+| pte_mkwrite | Creates a writable PTE |
++---------------------------+--------------------------------------------------+
+| pte_mkwrprotect | Creates a write protected PTE |
++---------------------------+--------------------------------------------------+
+| pte_mkspecial | Creates a special PTE |
++---------------------------+--------------------------------------------------+
+| pte_mkdevmap | Creates a ZONE_DEVICE mapped PTE |
++---------------------------+--------------------------------------------------+
+| pte_mksoft_dirty | Creates a soft dirty PTE |
++---------------------------+--------------------------------------------------+
+| pte_clear_soft_dirty | Clears a soft dirty PTE |
++---------------------------+--------------------------------------------------+
+| pte_swp_mksoft_dirty | Creates a soft dirty swapped PTE |
++---------------------------+--------------------------------------------------+
+| pte_swp_clear_soft_dirty | Clears a soft dirty swapped PTE |
++---------------------------+--------------------------------------------------+
+| pte_mknotpresent | Invalidates a mapped PTE |
++---------------------------+--------------------------------------------------+
+| ptep_get_and_clear | Clears a PTE |
++---------------------------+--------------------------------------------------+
+| ptep_get_and_clear_full | Clears a PTE |
++---------------------------+--------------------------------------------------+
+| ptep_test_and_clear_young | Clears young from a PTE |
++---------------------------+--------------------------------------------------+
+| ptep_set_wrprotect | Converts into a write protected PTE |
++---------------------------+--------------------------------------------------+
+| ptep_set_access_flags | Converts into a more permissive PTE |
++---------------------------+--------------------------------------------------+
+
+======================
+PMD Page Table Helpers
+======================
+
++---------------------------+--------------------------------------------------+
+| pmd_same | Tests whether both PMD entries are the same |
++---------------------------+--------------------------------------------------+
+| pmd_bad | Tests a non-table mapped PMD |
++---------------------------+--------------------------------------------------+
+| pmd_leaf | Tests a leaf mapped PMD |
++---------------------------+--------------------------------------------------+
+| pmd_huge | Tests a HugeTLB mapped PMD |
++---------------------------+--------------------------------------------------+
+| pmd_trans_huge | Tests a Transparent Huge Page (THP) at PMD |
++---------------------------+--------------------------------------------------+
+| pmd_present | Tests a valid mapped PMD |
++---------------------------+--------------------------------------------------+
+| pmd_young | Tests a young PMD |
++---------------------------+--------------------------------------------------+
+| pmd_dirty | Tests a dirty PMD |
++---------------------------+--------------------------------------------------+
+| pmd_write | Tests a writable PMD |
++---------------------------+--------------------------------------------------+
+| pmd_special | Tests a special PMD |
++---------------------------+--------------------------------------------------+
+| pmd_protnone | Tests a PROT_NONE PMD |
++---------------------------+--------------------------------------------------+
+| pmd_devmap | Tests a ZONE_DEVICE mapped PMD |
++---------------------------+--------------------------------------------------+
+| pmd_soft_dirty | Tests a soft dirty PMD |
++---------------------------+--------------------------------------------------+
+| pmd_swp_soft_dirty | Tests a soft dirty swapped PMD |
++---------------------------+--------------------------------------------------+
+| pmd_mkyoung | Creates a young PMD |
++---------------------------+--------------------------------------------------+
+| pmd_mkold | Creates an old PMD |
++---------------------------+--------------------------------------------------+
+| pmd_mkdirty | Creates a dirty PMD |
++---------------------------+--------------------------------------------------+
+| pmd_mkclean | Creates a clean PMD |
++---------------------------+--------------------------------------------------+
+| pmd_mkwrite | Creates a writable PMD |
++---------------------------+--------------------------------------------------+
+| pmd_mkwrprotect | Creates a write protected PMD |
++---------------------------+--------------------------------------------------+
+| pmd_mkspecial | Creates a special PMD |
++---------------------------+--------------------------------------------------+
+| pmd_mkdevmap | Creates a ZONE_DEVICE mapped PMD |
++---------------------------+--------------------------------------------------+
+| pmd_mksoft_dirty | Creates a soft dirty PMD |
++---------------------------+--------------------------------------------------+
+| pmd_clear_soft_dirty | Clears a soft dirty PMD |
++---------------------------+--------------------------------------------------+
+| pmd_swp_mksoft_dirty | Creates a soft dirty swapped PMD |
++---------------------------+--------------------------------------------------+
+| pmd_swp_clear_soft_dirty | Clears a soft dirty swapped PMD |
++---------------------------+--------------------------------------------------+
+| pmd_mkinvalid | Invalidates a mapped PMD [1] |
++---------------------------+--------------------------------------------------+
+| pmd_set_huge | Creates a PMD huge mapping |
++---------------------------+--------------------------------------------------+
+| pmd_clear_huge | Clears a PMD huge mapping |
++---------------------------+--------------------------------------------------+
+| pmdp_get_and_clear | Clears a PMD |
++---------------------------+--------------------------------------------------+
+| pmdp_get_and_clear_full | Clears a PMD |
++---------------------------+--------------------------------------------------+
+| pmdp_test_and_clear_young | Clears young from a PMD |
++---------------------------+--------------------------------------------------+
+| pmdp_set_wrprotect | Converts into a write protected PMD |
++---------------------------+--------------------------------------------------+
+| pmdp_set_access_flags | Converts into a more permissive PMD |
++---------------------------+--------------------------------------------------+
+
+======================
+PUD Page Table Helpers
+======================
+
++---------------------------+--------------------------------------------------+
+| pud_same | Tests whether both PUD entries are the same |
++---------------------------+--------------------------------------------------+
+| pud_bad | Tests a non-table mapped PUD |
++---------------------------+--------------------------------------------------+
+| pud_leaf | Tests a leaf mapped PUD |
++---------------------------+--------------------------------------------------+
+| pud_huge | Tests a HugeTLB mapped PUD |
++---------------------------+--------------------------------------------------+
+| pud_trans_huge | Tests a Transparent Huge Page (THP) at PUD |
++---------------------------+--------------------------------------------------+
+| pud_present | Tests a valid mapped PUD |
++---------------------------+--------------------------------------------------+
+| pud_young | Tests a young PUD |
++---------------------------+--------------------------------------------------+
+| pud_dirty | Tests a dirty PUD |
++---------------------------+--------------------------------------------------+
+| pud_write | Tests a writable PUD |
++---------------------------+--------------------------------------------------+
+| pud_devmap | Tests a ZONE_DEVICE mapped PUD |
++---------------------------+--------------------------------------------------+
+| pud_mkyoung | Creates a young PUD |
++---------------------------+--------------------------------------------------+
+| pud_mkold | Creates an old PUD |
++---------------------------+--------------------------------------------------+
+| pud_mkdirty | Creates a dirty PUD |
++---------------------------+--------------------------------------------------+
+| pud_mkclean | Creates a clean PUD |
++---------------------------+--------------------------------------------------+
+| pud_mkwrite | Creates a writable PUD |
++---------------------------+--------------------------------------------------+
+| pud_mkwrprotect | Creates a write protected PUD |
++---------------------------+--------------------------------------------------+
+| pud_mkdevmap | Creates a ZONE_DEVICE mapped PUD |
++---------------------------+--------------------------------------------------+
+| pud_mkinvalid | Invalidates a mapped PUD [1] |
++---------------------------+--------------------------------------------------+
+| pud_set_huge | Creates a PUD huge mapping |
++---------------------------+--------------------------------------------------+
+| pud_clear_huge | Clears a PUD huge mapping |
++---------------------------+--------------------------------------------------+
+| pudp_get_and_clear | Clears a PUD |
++---------------------------+--------------------------------------------------+
+| pudp_get_and_clear_full | Clears a PUD |
++---------------------------+--------------------------------------------------+
+| pudp_test_and_clear_young | Clears young from a PUD |
++---------------------------+--------------------------------------------------+
+| pudp_set_wrprotect | Converts into a write protected PUD |
++---------------------------+--------------------------------------------------+
+| pudp_set_access_flags | Converts into a more permissive PUD |
++---------------------------+--------------------------------------------------+
+
+==========================
+HugeTLB Page Table Helpers
+==========================
+
++---------------------------+--------------------------------------------------+
+| pte_huge | Tests a HugeTLB |
++---------------------------+--------------------------------------------------+
+| pte_mkhuge | Creates a HugeTLB |
++---------------------------+--------------------------------------------------+
+| huge_pte_dirty | Tests a dirty HugeTLB |
++---------------------------+--------------------------------------------------+
+| huge_pte_write | Tests a writable HugeTLB |
++---------------------------+--------------------------------------------------+
+| huge_pte_mkdirty | Creates a dirty HugeTLB |
++---------------------------+--------------------------------------------------+
+| huge_pte_mkwrite | Creates a writable HugeTLB |
++---------------------------+--------------------------------------------------+
+| huge_pte_mkwrprotect | Creates a write protected HugeTLB |
++---------------------------+--------------------------------------------------+
+| huge_ptep_get_and_clear | Clears a HugeTLB |
++---------------------------+--------------------------------------------------+
+| huge_ptep_set_wrprotect | Converts into a write protected HugeTLB |
++---------------------------+--------------------------------------------------+
+| huge_ptep_set_access_flags | Converts into a more permissive HugeTLB |
++---------------------------+--------------------------------------------------+
+
+========================
+SWAP Page Table Helpers
+========================
+
++---------------------------+--------------------------------------------------+
+| __pte_to_swp_entry | Creates a swapped entry (arch) from a mapped PTE |
++---------------------------+--------------------------------------------------+
+| __swp_to_pte_entry | Creates a mapped PTE from a swapped entry (arch) |
++---------------------------+--------------------------------------------------+
+| __pmd_to_swp_entry | Creates a swapped entry (arch) from a mapped PMD |
++---------------------------+--------------------------------------------------+
+| __swp_to_pmd_entry | Creates a mapped PMD from a swapped entry (arch) |
++---------------------------+--------------------------------------------------+
+| is_migration_entry | Tests a migration (read or write) swapped entry |
++---------------------------+--------------------------------------------------+
+| is_write_migration_entry | Tests a write migration swapped entry |
++---------------------------+--------------------------------------------------+
+| make_migration_entry_read | Converts into read migration swapped entry |
++---------------------------+--------------------------------------------------+
+| make_migration_entry | Creates a migration swapped entry (read or write)|
++---------------------------+--------------------------------------------------+
+
+[1] https://lore.kernel.org/linux-mm/20181017020930.GN30832@redhat.com/
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 0db4390435be..e86c3d824693 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -31,6 +31,12 @@
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
+/*
+ * Please refer Documentation/vm/arch_pgtable_helpers.rst for the semantics
+ * expectations that are being validated here. All future changes in here
+ * or the documentation need to be in sync.
+ */
+
#define VMFLAGS (VM_READ|VM_WRITE|VM_EXEC)
/*
--
2.20.1
^ permalink raw reply related
* [PATCH V5 3/4] mm/debug_vm_pgtable: Add debug prints for individual tests
From: Anshuman Khandual @ 2020-07-13 3:23 UTC (permalink / raw)
To: linux-mm
Cc: Catalin Marinas, Heiko Carstens, Paul Mackerras, H. Peter Anvin,
agordeev, Will Deacon, linux-riscv, linux-arch, linux-s390, x86,
Mike Rapoport, Christian Borntraeger, Ingo Molnar,
linux-arm-kernel, ziy, linux-snps-arc, Vasily Gorbik,
Anshuman Khandual, cai, Paul Walmsley, Kirill A . Shutemov,
Thomas Gleixner, gerald.schaefer, christophe.leroy, Vineet Gupta,
linux-kernel, Palmer Dabbelt, aneesh.kumar, Borislav Petkov,
Andrew Morton, linuxppc-dev, rppt
In-Reply-To: <1594610587-4172-1-git-send-email-anshuman.khandual@arm.com>
This adds debug print information that enlists all tests getting executed
on a given platform. With dynamic debug enabled, the following information
will be splashed during boot. For compactness purpose, dropped both time
stamp and prefix (i.e debug_vm_pgtable) from this sample output.
[debug_vm_pgtable ]: Validating architecture page table helpers
[pte_basic_tests ]: Validating PTE basic
[pmd_basic_tests ]: Validating PMD basic
[p4d_basic_tests ]: Validating P4D basic
[pgd_basic_tests ]: Validating PGD basic
[pte_clear_tests ]: Validating PTE clear
[pmd_clear_tests ]: Validating PMD clear
[pte_advanced_tests ]: Validating PTE advanced
[pmd_advanced_tests ]: Validating PMD advanced
[hugetlb_advanced_tests]: Validating HugeTLB advanced
[pmd_leaf_tests ]: Validating PMD leaf
[pmd_huge_tests ]: Validating PMD huge
[pte_savedwrite_tests ]: Validating PTE saved write
[pmd_savedwrite_tests ]: Validating PMD saved write
[pmd_populate_tests ]: Validating PMD populate
[pte_special_tests ]: Validating PTE special
[pte_protnone_tests ]: Validating PTE protnone
[pmd_protnone_tests ]: Validating PMD protnone
[pte_devmap_tests ]: Validating PTE devmap
[pmd_devmap_tests ]: Validating PMD devmap
[pte_swap_tests ]: Validating PTE swap
[swap_migration_tests ]: Validating swap migration
[hugetlb_basic_tests ]: Validating HugeTLB basic
[pmd_thp_tests ]: Validating PMD based THP
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-riscv@lists.infradead.org
Cc: x86@kernel.org
Cc: linux-mm@kvack.org
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Tested-by: Vineet Gupta <vgupta@synopsys.com> #arc
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
mm/debug_vm_pgtable.c | 46 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 45 insertions(+), 1 deletion(-)
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 9c7c11eecf17..0db4390435be 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -8,7 +8,7 @@
*
* Author: Anshuman Khandual <anshuman.khandual@arm.com>
*/
-#define pr_fmt(fmt) "debug_vm_pgtable: %s: " fmt, __func__
+#define pr_fmt(fmt) "debug_vm_pgtable: [%-25s]: " fmt, __func__
#include <linux/gfp.h>
#include <linux/highmem.h>
@@ -48,6 +48,7 @@ static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot)
{
pte_t pte = pfn_pte(pfn, prot);
+ pr_debug("Validating PTE basic\n");
WARN_ON(!pte_same(pte, pte));
WARN_ON(!pte_young(pte_mkyoung(pte_mkold(pte))));
WARN_ON(!pte_dirty(pte_mkdirty(pte_mkclean(pte))));
@@ -64,6 +65,7 @@ static void __init pte_advanced_tests(struct mm_struct *mm,
{
pte_t pte = pfn_pte(pfn, prot);
+ pr_debug("Validating PTE advanced\n");
pte = pfn_pte(pfn, prot);
set_pte_at(mm, vaddr, ptep, pte);
ptep_set_wrprotect(mm, vaddr, ptep);
@@ -103,6 +105,7 @@ static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot)
{
pte_t pte = pfn_pte(pfn, prot);
+ pr_debug("Validating PTE saved write\n");
WARN_ON(!pte_savedwrite(pte_mk_savedwrite(pte_clear_savedwrite(pte))));
WARN_ON(pte_savedwrite(pte_clear_savedwrite(pte_mk_savedwrite(pte))));
}
@@ -114,6 +117,7 @@ static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot)
if (!has_transparent_hugepage())
return;
+ pr_debug("Validating PMD basic\n");
WARN_ON(!pmd_same(pmd, pmd));
WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd))));
WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd))));
@@ -138,6 +142,7 @@ static void __init pmd_advanced_tests(struct mm_struct *mm,
if (!has_transparent_hugepage())
return;
+ pr_debug("Validating PMD advanced\n");
/* Align the address wrt HPAGE_PMD_SIZE */
vaddr = (vaddr & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE;
@@ -180,6 +185,7 @@ static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot)
{
pmd_t pmd = pfn_pmd(pfn, prot);
+ pr_debug("Validating PMD leaf\n");
/*
* PMD based THP is a leaf entry.
*/
@@ -193,6 +199,8 @@ static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP))
return;
+
+ pr_debug("Validating PMD huge\n");
/*
* X86 defined pmd_set_huge() verifies that the given
* PMD is not a populated non-leaf entry.
@@ -208,6 +216,7 @@ static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
{
pmd_t pmd = pfn_pmd(pfn, prot);
+ pr_debug("Validating PMD saved write\n");
WARN_ON(!pmd_savedwrite(pmd_mk_savedwrite(pmd_clear_savedwrite(pmd))));
WARN_ON(pmd_savedwrite(pmd_clear_savedwrite(pmd_mk_savedwrite(pmd))));
}
@@ -220,6 +229,7 @@ static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot)
if (!has_transparent_hugepage())
return;
+ pr_debug("Validating PUD basic\n");
WARN_ON(!pud_same(pud, pud));
WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud))));
WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud))));
@@ -246,6 +256,7 @@ static void __init pud_advanced_tests(struct mm_struct *mm,
if (!has_transparent_hugepage())
return;
+ pr_debug("Validating PUD advanced\n");
/* Align the address wrt HPAGE_PUD_SIZE */
vaddr = (vaddr & HPAGE_PUD_MASK) + HPAGE_PUD_SIZE;
@@ -288,6 +299,7 @@ static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot)
{
pud_t pud = pfn_pud(pfn, prot);
+ pr_debug("Validating PUD leaf\n");
/*
* PUD based THP is a leaf entry.
*/
@@ -301,6 +313,8 @@ static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP))
return;
+
+ pr_debug("Validating PUD huge\n");
/*
* X86 defined pud_set_huge() verifies that the given
* PUD is not a populated non-leaf entry.
@@ -354,6 +368,7 @@ static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
{
p4d_t p4d;
+ pr_debug("Validating P4D basic\n");
memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t));
WARN_ON(!p4d_same(p4d, p4d));
}
@@ -362,6 +377,7 @@ static void __init pgd_basic_tests(unsigned long pfn, pgprot_t prot)
{
pgd_t pgd;
+ pr_debug("Validating PGD basic\n");
memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t));
WARN_ON(!pgd_same(pgd, pgd));
}
@@ -374,6 +390,7 @@ static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp)
if (mm_pmd_folded(mm))
return;
+ pr_debug("Validating PUD clear\n");
pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
WRITE_ONCE(*pudp, pud);
pud_clear(pudp);
@@ -388,6 +405,8 @@ static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
if (mm_pmd_folded(mm))
return;
+
+ pr_debug("Validating PUD populate\n");
/*
* This entry points to next level page table page.
* Hence this must not qualify as pud_bad().
@@ -414,6 +433,7 @@ static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp)
if (mm_pud_folded(mm))
return;
+ pr_debug("Validating P4D clear\n");
p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
WRITE_ONCE(*p4dp, p4d);
p4d_clear(p4dp);
@@ -429,6 +449,7 @@ static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
if (mm_pud_folded(mm))
return;
+ pr_debug("Validating P4D populate\n");
/*
* This entry points to next level page table page.
* Hence this must not qualify as p4d_bad().
@@ -447,6 +468,7 @@ static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp)
if (mm_p4d_folded(mm))
return;
+ pr_debug("Validating PGD clear\n");
pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
WRITE_ONCE(*pgdp, pgd);
pgd_clear(pgdp);
@@ -462,6 +484,7 @@ static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
if (mm_p4d_folded(mm))
return;
+ pr_debug("Validating PGD populate\n");
/*
* This entry points to next level page table page.
* Hence this must not qualify as pgd_bad().
@@ -490,6 +513,7 @@ static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep,
{
pte_t pte = ptep_get(ptep);
+ pr_debug("Validating PTE clear\n");
pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
set_pte_at(mm, vaddr, ptep, pte);
barrier();
@@ -502,6 +526,7 @@ static void __init pmd_clear_tests(struct mm_struct *mm, pmd_t *pmdp)
{
pmd_t pmd = READ_ONCE(*pmdp);
+ pr_debug("Validating PMD clear\n");
pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE);
WRITE_ONCE(*pmdp, pmd);
pmd_clear(pmdp);
@@ -514,6 +539,7 @@ static void __init pmd_populate_tests(struct mm_struct *mm, pmd_t *pmdp,
{
pmd_t pmd;
+ pr_debug("Validating PMD populate\n");
/*
* This entry points to next level page table page.
* Hence this must not qualify as pmd_bad().
@@ -531,6 +557,7 @@ static void __init pte_special_tests(unsigned long pfn, pgprot_t prot)
if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL))
return;
+ pr_debug("Validating PTE special\n");
WARN_ON(!pte_special(pte_mkspecial(pte)));
}
@@ -541,6 +568,7 @@ static void __init pte_protnone_tests(unsigned long pfn, pgprot_t prot)
if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
return;
+ pr_debug("Validating PTE protnone\n");
WARN_ON(!pte_protnone(pte));
WARN_ON(!pte_present(pte));
}
@@ -553,6 +581,7 @@ static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot)
if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
return;
+ pr_debug("Validating PMD protnone\n");
WARN_ON(!pmd_protnone(pmd));
WARN_ON(!pmd_present(pmd));
}
@@ -565,6 +594,7 @@ static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot)
{
pte_t pte = pfn_pte(pfn, prot);
+ pr_debug("Validating PTE devmap\n");
WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
}
@@ -573,6 +603,7 @@ static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot)
{
pmd_t pmd = pfn_pmd(pfn, prot);
+ pr_debug("Validating PMD devmap\n");
WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd)));
}
@@ -581,6 +612,7 @@ static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot)
{
pud_t pud = pfn_pud(pfn, prot);
+ pr_debug("Validating PUD devmap\n");
WARN_ON(!pud_devmap(pud_mkdevmap(pud)));
}
#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
@@ -603,6 +635,7 @@ static void __init pte_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
return;
+ pr_debug("Validating PTE soft dirty\n");
WARN_ON(!pte_soft_dirty(pte_mksoft_dirty(pte)));
WARN_ON(pte_soft_dirty(pte_clear_soft_dirty(pte)));
}
@@ -614,6 +647,7 @@ static void __init pte_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
return;
+ pr_debug("Validating PTE swap soft dirty\n");
WARN_ON(!pte_swp_soft_dirty(pte_swp_mksoft_dirty(pte)));
WARN_ON(pte_swp_soft_dirty(pte_swp_clear_soft_dirty(pte)));
}
@@ -626,6 +660,7 @@ static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
return;
+ pr_debug("Validating PMD soft dirty\n");
WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd)));
WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd)));
}
@@ -638,6 +673,7 @@ static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
!IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION))
return;
+ pr_debug("Validating PMD swap soft dirty\n");
WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd)));
WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd)));
}
@@ -653,6 +689,7 @@ static void __init pte_swap_tests(unsigned long pfn, pgprot_t prot)
swp_entry_t swp;
pte_t pte;
+ pr_debug("Validating PTE swap\n");
pte = pfn_pte(pfn, prot);
swp = __pte_to_swp_entry(pte);
pte = __swp_entry_to_pte(swp);
@@ -665,6 +702,7 @@ static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot)
swp_entry_t swp;
pmd_t pmd;
+ pr_debug("Validating PMD swap\n");
pmd = pfn_pmd(pfn, prot);
swp = __pmd_to_swp_entry(pmd);
pmd = __swp_entry_to_pmd(swp);
@@ -681,6 +719,8 @@ static void __init swap_migration_tests(void)
if (!IS_ENABLED(CONFIG_MIGRATION))
return;
+
+ pr_debug("Validating swap migration\n");
/*
* swap_migration_tests() requires a dedicated page as it needs to
* be locked before creating a migration entry from it. Locking the
@@ -720,6 +760,7 @@ static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot)
struct page *page;
pte_t pte;
+ pr_debug("Validating HugeTLB basic\n");
/*
* Accessing the page associated with the pfn is safe here,
* as it was previously derived from a real kernel symbol.
@@ -747,6 +788,7 @@ static void __init hugetlb_advanced_tests(struct mm_struct *mm,
pte_t pte = ptep_get(ptep);
unsigned long paddr = __pfn_to_phys(pfn) & PMD_MASK;
+ pr_debug("Validating HugeTLB advanced\n");
pte = pte_mkhuge(mk_pte(pfn_to_page(PHYS_PFN(paddr)), prot));
set_huge_pte_at(mm, vaddr, ptep, pte);
barrier();
@@ -797,6 +839,7 @@ static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot)
if (!has_transparent_hugepage())
return;
+ pr_debug("Validating PMD based THP\n");
/*
* pmd_trans_huge() and pmd_present() must return positive after
* MMU invalidation with pmd_mkinvalid(). This behavior is an
@@ -825,6 +868,7 @@ static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot)
if (!has_transparent_hugepage())
return;
+ pr_debug("Validating PUD based THP\n");
pud = pfn_pud(pfn, prot);
WARN_ON(!pud_trans_huge(pud_mkhuge(pud)));
--
2.20.1
^ permalink raw reply related
* [PATCH V5 2/4] mm/debug_vm_pgtable: Add tests validating advanced arch page table helpers
From: Anshuman Khandual @ 2020-07-13 3:23 UTC (permalink / raw)
To: linux-mm
Cc: Catalin Marinas, Heiko Carstens, Paul Mackerras, H. Peter Anvin,
agordeev, Will Deacon, linux-riscv, linux-arch, linux-s390, x86,
Mike Rapoport, Christian Borntraeger, Ingo Molnar,
linux-arm-kernel, ziy, linux-snps-arc, Vasily Gorbik,
Anshuman Khandual, cai, Paul Walmsley, Kirill A . Shutemov,
Thomas Gleixner, gerald.schaefer, christophe.leroy, Vineet Gupta,
linux-kernel, Palmer Dabbelt, aneesh.kumar, Borislav Petkov,
Andrew Morton, linuxppc-dev, rppt
In-Reply-To: <1594610587-4172-1-git-send-email-anshuman.khandual@arm.com>
This adds new tests validating for these following arch advanced page table
helpers. These tests create and test specific mapping types at various page
table levels.
1. pxxp_set_wrprotect()
2. pxxp_get_and_clear()
3. pxxp_set_access_flags()
4. pxxp_get_and_clear_full()
5. pxxp_test_and_clear_young()
6. pxx_leaf()
7. pxx_set_huge()
8. pxx_(clear|mk)_savedwrite()
9. huge_pxxp_xxx()
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-riscv@lists.infradead.org
Cc: x86@kernel.org
Cc: linux-mm@kvack.org
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Tested-by: Vineet Gupta <vgupta@synopsys.com> #arc
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
mm/debug_vm_pgtable.c | 312 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 312 insertions(+)
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 2fac47db3eb7..9c7c11eecf17 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -21,6 +21,7 @@
#include <linux/module.h>
#include <linux/pfn_t.h>
#include <linux/printk.h>
+#include <linux/pgtable.h>
#include <linux/random.h>
#include <linux/spinlock.h>
#include <linux/swap.h>
@@ -28,6 +29,7 @@
#include <linux/start_kernel.h>
#include <linux/sched/mm.h>
#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
#define VMFLAGS (VM_READ|VM_WRITE|VM_EXEC)
@@ -55,6 +57,55 @@ static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot)
WARN_ON(pte_write(pte_wrprotect(pte_mkwrite(pte))));
}
+static void __init pte_advanced_tests(struct mm_struct *mm,
+ struct vm_area_struct *vma, pte_t *ptep,
+ unsigned long pfn, unsigned long vaddr,
+ pgprot_t prot)
+{
+ pte_t pte = pfn_pte(pfn, prot);
+
+ pte = pfn_pte(pfn, prot);
+ set_pte_at(mm, vaddr, ptep, pte);
+ ptep_set_wrprotect(mm, vaddr, ptep);
+ pte = ptep_get(ptep);
+ WARN_ON(pte_write(pte));
+
+ pte = pfn_pte(pfn, prot);
+ set_pte_at(mm, vaddr, ptep, pte);
+ ptep_get_and_clear(mm, vaddr, ptep);
+ pte = ptep_get(ptep);
+ WARN_ON(!pte_none(pte));
+
+ pte = pfn_pte(pfn, prot);
+ pte = pte_wrprotect(pte);
+ pte = pte_mkclean(pte);
+ set_pte_at(mm, vaddr, ptep, pte);
+ pte = pte_mkwrite(pte);
+ pte = pte_mkdirty(pte);
+ ptep_set_access_flags(vma, vaddr, ptep, pte, 1);
+ pte = ptep_get(ptep);
+ WARN_ON(!(pte_write(pte) && pte_dirty(pte)));
+
+ pte = pfn_pte(pfn, prot);
+ set_pte_at(mm, vaddr, ptep, pte);
+ ptep_get_and_clear_full(mm, vaddr, ptep, 1);
+ pte = ptep_get(ptep);
+ WARN_ON(!pte_none(pte));
+
+ pte = pte_mkyoung(pte);
+ set_pte_at(mm, vaddr, ptep, pte);
+ ptep_test_and_clear_young(vma, vaddr, ptep);
+ pte = ptep_get(ptep);
+ WARN_ON(pte_young(pte));
+}
+
+static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot)
+{
+ pte_t pte = pfn_pte(pfn, prot);
+
+ WARN_ON(!pte_savedwrite(pte_mk_savedwrite(pte_clear_savedwrite(pte))));
+ WARN_ON(pte_savedwrite(pte_clear_savedwrite(pte_mk_savedwrite(pte))));
+}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot)
{
@@ -77,6 +128,90 @@ static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot)
WARN_ON(!pmd_bad(pmd_mkhuge(pmd)));
}
+static void __init pmd_advanced_tests(struct mm_struct *mm,
+ struct vm_area_struct *vma, pmd_t *pmdp,
+ unsigned long pfn, unsigned long vaddr,
+ pgprot_t prot)
+{
+ pmd_t pmd = pfn_pmd(pfn, prot);
+
+ if (!has_transparent_hugepage())
+ return;
+
+ /* Align the address wrt HPAGE_PMD_SIZE */
+ vaddr = (vaddr & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE;
+
+ pmd = pfn_pmd(pfn, prot);
+ set_pmd_at(mm, vaddr, pmdp, pmd);
+ pmdp_set_wrprotect(mm, vaddr, pmdp);
+ pmd = READ_ONCE(*pmdp);
+ WARN_ON(pmd_write(pmd));
+
+ pmd = pfn_pmd(pfn, prot);
+ set_pmd_at(mm, vaddr, pmdp, pmd);
+ pmdp_huge_get_and_clear(mm, vaddr, pmdp);
+ pmd = READ_ONCE(*pmdp);
+ WARN_ON(!pmd_none(pmd));
+
+ pmd = pfn_pmd(pfn, prot);
+ pmd = pmd_wrprotect(pmd);
+ pmd = pmd_mkclean(pmd);
+ set_pmd_at(mm, vaddr, pmdp, pmd);
+ pmd = pmd_mkwrite(pmd);
+ pmd = pmd_mkdirty(pmd);
+ pmdp_set_access_flags(vma, vaddr, pmdp, pmd, 1);
+ pmd = READ_ONCE(*pmdp);
+ WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));
+
+ pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
+ set_pmd_at(mm, vaddr, pmdp, pmd);
+ pmdp_huge_get_and_clear_full(vma, vaddr, pmdp, 1);
+ pmd = READ_ONCE(*pmdp);
+ WARN_ON(!pmd_none(pmd));
+
+ pmd = pmd_mkyoung(pmd);
+ set_pmd_at(mm, vaddr, pmdp, pmd);
+ pmdp_test_and_clear_young(vma, vaddr, pmdp);
+ pmd = READ_ONCE(*pmdp);
+ WARN_ON(pmd_young(pmd));
+}
+
+static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot)
+{
+ pmd_t pmd = pfn_pmd(pfn, prot);
+
+ /*
+ * PMD based THP is a leaf entry.
+ */
+ pmd = pmd_mkhuge(pmd);
+ WARN_ON(!pmd_leaf(pmd));
+}
+
+static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
+{
+ pmd_t pmd;
+
+ if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP))
+ return;
+ /*
+ * X86 defined pmd_set_huge() verifies that the given
+ * PMD is not a populated non-leaf entry.
+ */
+ WRITE_ONCE(*pmdp, __pmd(0));
+ WARN_ON(!pmd_set_huge(pmdp, __pfn_to_phys(pfn), prot));
+ WARN_ON(!pmd_clear_huge(pmdp));
+ pmd = READ_ONCE(*pmdp);
+ WARN_ON(!pmd_none(pmd));
+}
+
+static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
+{
+ pmd_t pmd = pfn_pmd(pfn, prot);
+
+ WARN_ON(!pmd_savedwrite(pmd_mk_savedwrite(pmd_clear_savedwrite(pmd))));
+ WARN_ON(pmd_savedwrite(pmd_clear_savedwrite(pmd_mk_savedwrite(pmd))));
+}
+
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot)
{
@@ -100,12 +235,119 @@ static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot)
*/
WARN_ON(!pud_bad(pud_mkhuge(pud)));
}
+
+static void __init pud_advanced_tests(struct mm_struct *mm,
+ struct vm_area_struct *vma, pud_t *pudp,
+ unsigned long pfn, unsigned long vaddr,
+ pgprot_t prot)
+{
+ pud_t pud = pfn_pud(pfn, prot);
+
+ if (!has_transparent_hugepage())
+ return;
+
+ /* Align the address wrt HPAGE_PUD_SIZE */
+ vaddr = (vaddr & HPAGE_PUD_MASK) + HPAGE_PUD_SIZE;
+
+ set_pud_at(mm, vaddr, pudp, pud);
+ pudp_set_wrprotect(mm, vaddr, pudp);
+ pud = READ_ONCE(*pudp);
+ WARN_ON(pud_write(pud));
+
+#ifndef __PAGETABLE_PMD_FOLDED
+ pud = pfn_pud(pfn, prot);
+ set_pud_at(mm, vaddr, pudp, pud);
+ pudp_huge_get_and_clear(mm, vaddr, pudp);
+ pud = READ_ONCE(*pudp);
+ WARN_ON(!pud_none(pud));
+
+ pud = pfn_pud(pfn, prot);
+ set_pud_at(mm, vaddr, pudp, pud);
+ pudp_huge_get_and_clear_full(mm, vaddr, pudp, 1);
+ pud = READ_ONCE(*pudp);
+ WARN_ON(!pud_none(pud));
+#endif /* __PAGETABLE_PMD_FOLDED */
+ pud = pfn_pud(pfn, prot);
+ pud = pud_wrprotect(pud);
+ pud = pud_mkclean(pud);
+ set_pud_at(mm, vaddr, pudp, pud);
+ pud = pud_mkwrite(pud);
+ pud = pud_mkdirty(pud);
+ pudp_set_access_flags(vma, vaddr, pudp, pud, 1);
+ pud = READ_ONCE(*pudp);
+ WARN_ON(!(pud_write(pud) && pud_dirty(pud)));
+
+ pud = pud_mkyoung(pud);
+ set_pud_at(mm, vaddr, pudp, pud);
+ pudp_test_and_clear_young(vma, vaddr, pudp);
+ pud = READ_ONCE(*pudp);
+ WARN_ON(pud_young(pud));
+}
+
+static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot)
+{
+ pud_t pud = pfn_pud(pfn, prot);
+
+ /*
+ * PUD based THP is a leaf entry.
+ */
+ pud = pud_mkhuge(pud);
+ WARN_ON(!pud_leaf(pud));
+}
+
+static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
+{
+ pud_t pud;
+
+ if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP))
+ return;
+ /*
+ * X86 defined pud_set_huge() verifies that the given
+ * PUD is not a populated non-leaf entry.
+ */
+ WRITE_ONCE(*pudp, __pud(0));
+ WARN_ON(!pud_set_huge(pudp, __pfn_to_phys(pfn), prot));
+ WARN_ON(!pud_clear_huge(pudp));
+ pud = READ_ONCE(*pudp);
+ WARN_ON(!pud_none(pud));
+}
#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pud_advanced_tests(struct mm_struct *mm,
+ struct vm_area_struct *vma, pud_t *pudp,
+ unsigned long pfn, unsigned long vaddr,
+ pgprot_t prot)
+{
+}
+static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
+{
+}
#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot) { }
static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pmd_advanced_tests(struct mm_struct *mm,
+ struct vm_area_struct *vma, pmd_t *pmdp,
+ unsigned long pfn, unsigned long vaddr,
+ pgprot_t prot)
+{
+}
+static void __init pud_advanced_tests(struct mm_struct *mm,
+ struct vm_area_struct *vma, pud_t *pudp,
+ unsigned long pfn, unsigned long vaddr,
+ pgprot_t prot)
+{
+}
+static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
+{
+}
+static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
+{
+}
+static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) { }
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
@@ -495,8 +737,56 @@ static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot)
WARN_ON(!pte_huge(pte_mkhuge(pte)));
#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
}
+
+static void __init hugetlb_advanced_tests(struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ pte_t *ptep, unsigned long pfn,
+ unsigned long vaddr, pgprot_t prot)
+{
+ struct page *page = pfn_to_page(pfn);
+ pte_t pte = ptep_get(ptep);
+ unsigned long paddr = __pfn_to_phys(pfn) & PMD_MASK;
+
+ pte = pte_mkhuge(mk_pte(pfn_to_page(PHYS_PFN(paddr)), prot));
+ set_huge_pte_at(mm, vaddr, ptep, pte);
+ barrier();
+ WARN_ON(!pte_same(pte, huge_ptep_get(ptep)));
+ huge_pte_clear(mm, vaddr, ptep, PMD_SIZE);
+ pte = huge_ptep_get(ptep);
+ WARN_ON(!huge_pte_none(pte));
+
+ pte = mk_huge_pte(page, prot);
+ set_huge_pte_at(mm, vaddr, ptep, pte);
+ barrier();
+ huge_ptep_set_wrprotect(mm, vaddr, ptep);
+ pte = huge_ptep_get(ptep);
+ WARN_ON(huge_pte_write(pte));
+
+ pte = mk_huge_pte(page, prot);
+ set_huge_pte_at(mm, vaddr, ptep, pte);
+ barrier();
+ huge_ptep_get_and_clear(mm, vaddr, ptep);
+ pte = huge_ptep_get(ptep);
+ WARN_ON(!huge_pte_none(pte));
+
+ pte = mk_huge_pte(page, prot);
+ pte = huge_pte_wrprotect(pte);
+ set_huge_pte_at(mm, vaddr, ptep, pte);
+ barrier();
+ pte = huge_pte_mkwrite(pte);
+ pte = huge_pte_mkdirty(pte);
+ huge_ptep_set_access_flags(vma, vaddr, ptep, pte, 1);
+ pte = huge_ptep_get(ptep);
+ WARN_ON(!(huge_pte_write(pte) && huge_pte_dirty(pte)));
+}
#else /* !CONFIG_HUGETLB_PAGE */
static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init hugetlb_advanced_tests(struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ pte_t *ptep, unsigned long pfn,
+ unsigned long vaddr, pgprot_t prot)
+{
+}
#endif /* CONFIG_HUGETLB_PAGE */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -568,6 +858,7 @@ static unsigned long __init get_random_vaddr(void)
static int __init debug_vm_pgtable(void)
{
+ struct vm_area_struct *vma;
struct mm_struct *mm;
pgd_t *pgdp;
p4d_t *p4dp, *saved_p4dp;
@@ -596,6 +887,12 @@ static int __init debug_vm_pgtable(void)
*/
protnone = __P000;
+ vma = vm_area_alloc(mm);
+ if (!vma) {
+ pr_err("vma allocation failed\n");
+ return 1;
+ }
+
/*
* PFN for mapping at PTE level is determined from a standard kernel
* text symbol. But pfns for higher page table levels are derived by
@@ -644,6 +941,20 @@ static int __init debug_vm_pgtable(void)
p4d_clear_tests(mm, p4dp);
pgd_clear_tests(mm, pgdp);
+ pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
+ pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot);
+ pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot);
+ hugetlb_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
+
+ pmd_leaf_tests(pmd_aligned, prot);
+ pud_leaf_tests(pud_aligned, prot);
+
+ pmd_huge_tests(pmdp, pmd_aligned, prot);
+ pud_huge_tests(pudp, pud_aligned, prot);
+
+ pte_savedwrite_tests(pte_aligned, prot);
+ pmd_savedwrite_tests(pmd_aligned, prot);
+
pte_unmap_unlock(ptep, ptl);
pmd_populate_tests(mm, pmdp, saved_ptep);
@@ -678,6 +989,7 @@ static int __init debug_vm_pgtable(void)
pmd_free(mm, saved_pmdp);
pte_free(mm, saved_ptep);
+ vm_area_free(vma);
mm_dec_nr_puds(mm);
mm_dec_nr_pmds(mm);
mm_dec_nr_ptes(mm);
--
2.20.1
^ permalink raw reply related
* [PATCH V5 1/4] mm/debug_vm_pgtable: Add tests validating arch helpers for core MM features
From: Anshuman Khandual @ 2020-07-13 3:23 UTC (permalink / raw)
To: linux-mm
Cc: Catalin Marinas, Heiko Carstens, Paul Mackerras, H. Peter Anvin,
agordeev, Will Deacon, linux-riscv, linux-arch, linux-s390, x86,
Mike Rapoport, Christian Borntraeger, Ingo Molnar,
linux-arm-kernel, ziy, linux-snps-arc, Vasily Gorbik,
Anshuman Khandual, cai, Paul Walmsley, Kirill A . Shutemov,
Thomas Gleixner, gerald.schaefer, christophe.leroy, Vineet Gupta,
linux-kernel, Palmer Dabbelt, aneesh.kumar, Borislav Petkov,
Andrew Morton, linuxppc-dev, rppt
In-Reply-To: <1594610587-4172-1-git-send-email-anshuman.khandual@arm.com>
This adds new tests validating arch page table helpers for these following
core memory features. These tests create and test specific mapping types at
various page table levels.
1. SPECIAL mapping
2. PROTNONE mapping
3. DEVMAP mapping
4. SOFTDIRTY mapping
5. SWAP mapping
6. MIGRATION mapping
7. HUGETLB mapping
8. THP mapping
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-riscv@lists.infradead.org
Cc: x86@kernel.org
Cc: linux-mm@kvack.org
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Tested-by: Vineet Gupta <vgupta@synopsys.com> #arc
Reviewed-by: Zi Yan <ziy@nvidia.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
mm/debug_vm_pgtable.c | 302 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 301 insertions(+), 1 deletion(-)
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 61ab16fb2e36..2fac47db3eb7 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -282,6 +282,278 @@ static void __init pmd_populate_tests(struct mm_struct *mm, pmd_t *pmdp,
WARN_ON(pmd_bad(pmd));
}
+static void __init pte_special_tests(unsigned long pfn, pgprot_t prot)
+{
+ pte_t pte = pfn_pte(pfn, prot);
+
+ if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL))
+ return;
+
+ WARN_ON(!pte_special(pte_mkspecial(pte)));
+}
+
+static void __init pte_protnone_tests(unsigned long pfn, pgprot_t prot)
+{
+ pte_t pte = pfn_pte(pfn, prot);
+
+ if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
+ return;
+
+ WARN_ON(!pte_protnone(pte));
+ WARN_ON(!pte_present(pte));
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot)
+{
+ pmd_t pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
+
+ if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
+ return;
+
+ WARN_ON(!pmd_protnone(pmd));
+ WARN_ON(!pmd_present(pmd));
+}
+#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
+static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
+static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot)
+{
+ pte_t pte = pfn_pte(pfn, prot);
+
+ WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot)
+{
+ pmd_t pmd = pfn_pmd(pfn, prot);
+
+ WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd)));
+}
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot)
+{
+ pud_t pud = pfn_pud(pfn, prot);
+
+ WARN_ON(!pud_devmap(pud_mkdevmap(pud)));
+}
+#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
+static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
+#else /* CONFIG_TRANSPARENT_HUGEPAGE */
+static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#else
+static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
+
+static void __init pte_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
+{
+ pte_t pte = pfn_pte(pfn, prot);
+
+ if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
+ return;
+
+ WARN_ON(!pte_soft_dirty(pte_mksoft_dirty(pte)));
+ WARN_ON(pte_soft_dirty(pte_clear_soft_dirty(pte)));
+}
+
+static void __init pte_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
+{
+ pte_t pte = pfn_pte(pfn, prot);
+
+ if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
+ return;
+
+ WARN_ON(!pte_swp_soft_dirty(pte_swp_mksoft_dirty(pte)));
+ WARN_ON(pte_swp_soft_dirty(pte_swp_clear_soft_dirty(pte)));
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
+{
+ pmd_t pmd = pfn_pmd(pfn, prot);
+
+ if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
+ return;
+
+ WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd)));
+ WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd)));
+}
+
+static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
+{
+ pmd_t pmd = pfn_pmd(pfn, prot);
+
+ if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) ||
+ !IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION))
+ return;
+
+ WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd)));
+ WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd)));
+}
+#else /* !CONFIG_ARCH_HAS_PTE_DEVMAP */
+static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
+{
+}
+#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
+
+static void __init pte_swap_tests(unsigned long pfn, pgprot_t prot)
+{
+ swp_entry_t swp;
+ pte_t pte;
+
+ pte = pfn_pte(pfn, prot);
+ swp = __pte_to_swp_entry(pte);
+ pte = __swp_entry_to_pte(swp);
+ WARN_ON(pfn != pte_pfn(pte));
+}
+
+#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
+static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot)
+{
+ swp_entry_t swp;
+ pmd_t pmd;
+
+ pmd = pfn_pmd(pfn, prot);
+ swp = __pmd_to_swp_entry(pmd);
+ pmd = __swp_entry_to_pmd(swp);
+ WARN_ON(pfn != pmd_pfn(pmd));
+}
+#else /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */
+static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
+
+static void __init swap_migration_tests(void)
+{
+ struct page *page;
+ swp_entry_t swp;
+
+ if (!IS_ENABLED(CONFIG_MIGRATION))
+ return;
+ /*
+ * swap_migration_tests() requires a dedicated page as it needs to
+ * be locked before creating a migration entry from it. Locking the
+ * page that actually maps kernel text ('start_kernel') can be real
+ * problematic. Lets allocate a dedicated page explicitly for this
+ * purpose that will be freed subsequently.
+ */
+ page = alloc_page(GFP_KERNEL);
+ if (!page) {
+ pr_err("page allocation failed\n");
+ return;
+ }
+
+ /*
+ * make_migration_entry() expects given page to be
+ * locked, otherwise it stumbles upon a BUG_ON().
+ */
+ __SetPageLocked(page);
+ swp = make_migration_entry(page, 1);
+ WARN_ON(!is_migration_entry(swp));
+ WARN_ON(!is_write_migration_entry(swp));
+
+ make_migration_entry_read(&swp);
+ WARN_ON(!is_migration_entry(swp));
+ WARN_ON(is_write_migration_entry(swp));
+
+ swp = make_migration_entry(page, 0);
+ WARN_ON(!is_migration_entry(swp));
+ WARN_ON(is_write_migration_entry(swp));
+ __ClearPageLocked(page);
+ __free_page(page);
+}
+
+#ifdef CONFIG_HUGETLB_PAGE
+static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+ struct page *page;
+ pte_t pte;
+
+ /*
+ * Accessing the page associated with the pfn is safe here,
+ * as it was previously derived from a real kernel symbol.
+ */
+ page = pfn_to_page(pfn);
+ pte = mk_huge_pte(page, prot);
+
+ WARN_ON(!huge_pte_dirty(huge_pte_mkdirty(pte)));
+ WARN_ON(!huge_pte_write(huge_pte_mkwrite(huge_pte_wrprotect(pte))));
+ WARN_ON(huge_pte_write(huge_pte_wrprotect(huge_pte_mkwrite(pte))));
+
+#ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
+ pte = pfn_pte(pfn, prot);
+
+ WARN_ON(!pte_huge(pte_mkhuge(pte)));
+#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
+}
+#else /* !CONFIG_HUGETLB_PAGE */
+static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_HUGETLB_PAGE */
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot)
+{
+ pmd_t pmd;
+
+ if (!has_transparent_hugepage())
+ return;
+
+ /*
+ * pmd_trans_huge() and pmd_present() must return positive after
+ * MMU invalidation with pmd_mkinvalid(). This behavior is an
+ * optimization for transparent huge page. pmd_trans_huge() must
+ * be true if pmd_page() returns a valid THP to avoid taking the
+ * pmd_lock when others walk over non transhuge pmds (i.e. there
+ * are no THP allocated). Especially when splitting a THP and
+ * removing the present bit from the pmd, pmd_trans_huge() still
+ * needs to return true. pmd_present() should be true whenever
+ * pmd_trans_huge() returns true.
+ */
+ pmd = pfn_pmd(pfn, prot);
+ WARN_ON(!pmd_trans_huge(pmd_mkhuge(pmd)));
+
+#ifndef __HAVE_ARCH_PMDP_INVALIDATE
+ WARN_ON(!pmd_trans_huge(pmd_mkinvalid(pmd_mkhuge(pmd))));
+ WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd))));
+#endif /* __HAVE_ARCH_PMDP_INVALIDATE */
+}
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot)
+{
+ pud_t pud;
+
+ if (!has_transparent_hugepage())
+ return;
+
+ pud = pfn_pud(pfn, prot);
+ WARN_ON(!pud_trans_huge(pud_mkhuge(pud)));
+
+ /*
+ * pud_mkinvalid() has been dropped for now. Enable back
+ * these tests when it comes back with a modified pud_present().
+ *
+ * WARN_ON(!pud_trans_huge(pud_mkinvalid(pud_mkhuge(pud))));
+ * WARN_ON(!pud_present(pud_mkinvalid(pud_mkhuge(pud))));
+ */
+}
+#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
+static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
+#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
+static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
static unsigned long __init get_random_vaddr(void)
{
unsigned long random_vaddr, random_pages, total_user_pages;
@@ -303,7 +575,7 @@ static int __init debug_vm_pgtable(void)
pmd_t *pmdp, *saved_pmdp, pmd;
pte_t *ptep;
pgtable_t saved_ptep;
- pgprot_t prot;
+ pgprot_t prot, protnone;
phys_addr_t paddr;
unsigned long vaddr, pte_aligned, pmd_aligned;
unsigned long pud_aligned, p4d_aligned, pgd_aligned;
@@ -318,6 +590,12 @@ static int __init debug_vm_pgtable(void)
return 1;
}
+ /*
+ * __P000 (or even __S000) will help create page table entries with
+ * PROT_NONE permission as required for pxx_protnone_tests().
+ */
+ protnone = __P000;
+
/*
* PFN for mapping at PTE level is determined from a standard kernel
* text symbol. But pfns for higher page table levels are derived by
@@ -373,6 +651,28 @@ static int __init debug_vm_pgtable(void)
p4d_populate_tests(mm, p4dp, saved_pudp);
pgd_populate_tests(mm, pgdp, saved_p4dp);
+ pte_special_tests(pte_aligned, prot);
+ pte_protnone_tests(pte_aligned, protnone);
+ pmd_protnone_tests(pmd_aligned, protnone);
+
+ pte_devmap_tests(pte_aligned, prot);
+ pmd_devmap_tests(pmd_aligned, prot);
+ pud_devmap_tests(pud_aligned, prot);
+
+ pte_soft_dirty_tests(pte_aligned, prot);
+ pmd_soft_dirty_tests(pmd_aligned, prot);
+ pte_swap_soft_dirty_tests(pte_aligned, prot);
+ pmd_swap_soft_dirty_tests(pmd_aligned, prot);
+
+ pte_swap_tests(pte_aligned, prot);
+ pmd_swap_tests(pmd_aligned, prot);
+
+ swap_migration_tests();
+ hugetlb_basic_tests(pte_aligned, prot);
+
+ pmd_thp_tests(pmd_aligned, prot);
+ pud_thp_tests(pud_aligned, prot);
+
p4d_free(mm, saved_p4dp);
pud_free(mm, saved_pudp);
pmd_free(mm, saved_pmdp);
--
2.20.1
^ permalink raw reply related
* [PATCH V5 0/4] mm/debug_vm_pgtable: Add some more tests
From: Anshuman Khandual @ 2020-07-13 3:23 UTC (permalink / raw)
To: linux-mm
Cc: linux-doc, Catalin Marinas, Heiko Carstens, Paul Mackerras,
H. Peter Anvin, agordeev, Will Deacon, linux-riscv, linux-arch,
linux-s390, Jonathan Corbet, x86, Mike Rapoport,
Christian Borntraeger, Ingo Molnar, linux-arm-kernel, ziy,
linux-snps-arc, Vasily Gorbik, Anshuman Khandual, cai,
Paul Walmsley, Kirill A . Shutemov, Thomas Gleixner,
gerald.schaefer, christophe.leroy, Vineet Gupta, linux-kernel,
Palmer Dabbelt, aneesh.kumar, Borislav Petkov, Andrew Morton,
linuxppc-dev, rppt
This series adds some more arch page table helper validation tests which
are related to core and advanced memory functions. This also creates a
documentation, enlisting expected semantics for all page table helpers as
suggested by Mike Rapoport previously (https://lkml.org/lkml/2020/1/30/40).
There are many TRANSPARENT_HUGEPAGE and ARCH_HAS_TRANSPARENT_HUGEPAGE_PUD
ifdefs scattered across the test. But consolidating all the fallback stubs
is not very straight forward because ARCH_HAS_TRANSPARENT_HUGEPAGE_PUD is
not explicitly dependent on ARCH_HAS_TRANSPARENT_HUGEPAGE.
Tested on arm64, x86 platforms but only build tested on all other enabled
platforms through ARCH_HAS_DEBUG_VM_PGTABLE i.e powerpc, arc, s390. The
following failure on arm64 still exists which was mentioned previously. It
will be fixed with the upcoming THP migration on arm64 enablement series.
WARNING .... mm/debug_vm_pgtable.c:866 debug_vm_pgtable+0x940/0xa54
WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd))))
This series is based on v5.8-rc5.
Changes in V5:
- Dropped RANDOM_ORVALUE from hugetlb_advanced_tests()
- Folded in Mike's patch for the rst document
- Fixed typos in the rst document
Changes in V4: (https://patchwork.kernel.org/project/linux-mm/list/?series=313173)
- Replaced READ_ONCE() with ptep_get() while accessing PTE pointers per Christophe
- Fixed function argument alignments per Christophe
Changes in V3: (https://patchwork.kernel.org/project/linux-mm/list/?series=302483)
- Replaced HAVE_ARCH_SOFT_DIRTY with MEM_SOFT_DIRTY
- Added HAVE_ARCH_HUGE_VMAP checks in pxx_huge_tests() per Gerald
- Updated documentation for pmd_thp_tests() per Zi Yan
- Replaced READ_ONCE() with huge_ptep_get() per Gerald
- Added pte_mkhuge() and masking with PMD_MASK per Gerald
- Replaced pte_same() with holding pfn check in pxx_swap_tests()
- Added documentation for all (#ifdef #else #endif) per Gerald
- Updated pmd_protnone_tests() per Gerald
- Updated HugeTLB PTE creation in hugetlb_advanced_tests() per Gerald
- Replaced [pmd|pud]_mknotpresent() with [pmd|pud]_mkinvalid()
- Added has_transparent_hugepage() check for PMD and PUD tests
- Added a patch which debug prints all individual tests being executed
- Updated documentation for renamed [pmd|pud]_mkinvalid() helpers
Changes in V2: (https://patchwork.kernel.org/project/linux-mm/list/?series=260573)
- Dropped CONFIG_ARCH_HAS_PTE_SPECIAL per Christophe
- Dropped CONFIG_NUMA_BALANCING per Christophe
- Dropped CONFIG_HAVE_ARCH_SOFT_DIRTY per Christophe
- Dropped CONFIG_MIGRATION per Christophe
- Replaced CONFIG_S390 with __HAVE_ARCH_PMDP_INVALIDATE
- Moved page allocation & free inside swap_migration_tests() per Christophe
- Added CONFIG_TRANSPARENT_HUGEPAGE to protect pfn_pmd()
- Added CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD to protect pfn_pud()
- Added a patch for other arch advanced page table helper tests
- Added a patch creating a documentation for page table helper semantics
Changes in V1: (https://patchwork.kernel.org/patch/11408253/)
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-riscv@lists.infradead.org
Cc: x86@kernel.org
Cc: linux-mm@kvack.org
Cc: linux-doc@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Anshuman Khandual (4):
mm/debug_vm_pgtable: Add tests validating arch helpers for core MM features
mm/debug_vm_pgtable: Add tests validating advanced arch page table helpers
mm/debug_vm_pgtable: Add debug prints for individual tests
Documentation/mm: Add descriptions for arch page table helpers
Documentation/vm/arch_pgtable_helpers.rst | 258 +++++++++
mm/debug_vm_pgtable.c | 666 +++++++++++++++++++++-
2 files changed, 922 insertions(+), 2 deletions(-)
create mode 100644 Documentation/vm/arch_pgtable_helpers.rst
--
2.20.1
^ permalink raw reply
* Re: [PATCH v4 5/7] KVM: PPC: clean up redundant kvm_run parameters in assembly
From: Tianjia Zhang @ 2020-07-13 3:07 UTC (permalink / raw)
To: Paul Mackerras
Cc: wanpengli, kvm, david, heiko.carstens, peterx, linux-mips, hpa,
kvmarm, linux-s390, frankja, chenhuacai, maz, joro, x86,
borntraeger, mingo, julien.thierry.kdev, thuth, gor,
suzuki.poulose, kvm-ppc, bp, tglx, linux-arm-kernel, jmattson,
tsbogend, cohuck, christoffer.dall, sean.j.christopherson,
linux-kernel, james.morse, pbonzini, vkuznets, linuxppc-dev
In-Reply-To: <20200526055924.GD282305@thinks.paulus.ozlabs.org>
On 2020/5/26 13:59, Paul Mackerras wrote:
> On Mon, Apr 27, 2020 at 12:35:12PM +0800, Tianjia Zhang wrote:
>> In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu'
>> structure. For historical reasons, many kvm-related function parameters
>> retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time. This
>> patch does a unified cleanup of these remaining redundant parameters.
>
> Some of these changes don't look completely correct to me, see below.
> If you're expecting these patches to go through my tree, I can fix up
> the patch and commit it (with you as author), noting the changes I
> made in the commit message. Do you want me to do that?
>
I am very glad for you to do so, although I have submitted a new version
of patch, I still prefer you to fix up and commit it.
Thanks and best,
Tianjia
>> diff --git a/arch/powerpc/kvm/book3s_interrupts.S b/arch/powerpc/kvm/book3s_interrupts.S
>> index f7ad99d972ce..0eff749d8027 100644
>> --- a/arch/powerpc/kvm/book3s_interrupts.S
>> +++ b/arch/powerpc/kvm/book3s_interrupts.S
>> @@ -55,8 +55,7 @@
>> ****************************************************************************/
>>
>> /* Registers:
>> - * r3: kvm_run pointer
>> - * r4: vcpu pointer
>> + * r3: vcpu pointer
>> */
>> _GLOBAL(__kvmppc_vcpu_run)
>>
>> @@ -68,8 +67,8 @@ kvm_start_entry:
>> /* Save host state to the stack */
>> PPC_STLU r1, -SWITCH_FRAME_SIZE(r1)
>>
>> - /* Save r3 (kvm_run) and r4 (vcpu) */
>> - SAVE_2GPRS(3, r1)
>> + /* Save r3 (vcpu) */
>> + SAVE_GPR(3, r1)
>>
>> /* Save non-volatile registers (r14 - r31) */
>> SAVE_NVGPRS(r1)
>> @@ -82,11 +81,11 @@ kvm_start_entry:
>> PPC_STL r0, _LINK(r1)
>>
>> /* Load non-volatile guest state from the vcpu */
>> - VCPU_LOAD_NVGPRS(r4)
>> + VCPU_LOAD_NVGPRS(r3)
>>
>> kvm_start_lightweight:
>> /* Copy registers into shadow vcpu so we can access them in real mode */
>> - mr r3, r4
>> + mr r4, r3
>
> This mr doesn't seem necessary.
>
>> bl FUNC(kvmppc_copy_to_svcpu)
>> nop
>> REST_GPR(4, r1)
>
> This should be loading r4 from GPR3(r1), not GPR4(r1) - which is what
> REST_GPR(4, r1) will do.
>
> Then, in the file but not in the patch context, there is this line:
>
> PPC_LL r3, GPR4(r1) /* vcpu pointer */
>
> where once again GPR4 needs to be GPR3.
>
>> @@ -191,10 +190,10 @@ after_sprg3_load:
>> PPC_STL r31, VCPU_GPR(R31)(r7)
>>
>> /* Pass the exit number as 3rd argument to kvmppc_handle_exit */
>
> The comment should be modified to say "2nd" instead of "3rd",
> otherwise it is confusing.
>
> The rest of the patch looks OK.
>
> Paul.
>
^ permalink raw reply
* Re: [PATCH v2 09/10] tools/perf: Add perf tools support for extended register capability in powerpc
From: Athira Rajeev @ 2020-07-13 2:36 UTC (permalink / raw)
To: Michael Ellerman; +Cc: Michael Neuling, maddy, linuxppc-dev
In-Reply-To: <87pn962owo.fsf@mpe.ellerman.id.au>
[-- Attachment #1: Type: text/plain, Size: 6296 bytes --]
> On 08-Jul-2020, at 5:34 PM, Michael Ellerman <mpe@ellerman.id.au> wrote:
>
> Athira Rajeev <atrajeev@linux.vnet.ibm.com <mailto:atrajeev@linux.vnet.ibm.com>> writes:
>> From: Anju T Sudhakar <anju@linux.vnet.ibm.com>
>>
>> Add extended regs to sample_reg_mask in the tool side to use
>> with `-I?` option. Perf tools side uses extended mask to display
>> the platform supported register names (with -I? option) to the user
>> and also send this mask to the kernel to capture the extended registers
>> in each sample. Hence decide the mask value based on the processor
>> version.
>>
>> Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
>> [Decide extended mask at run time based on platform]
>> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
>> Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
>
> Will need an ack from perf tools folks, who are not on Cc by the looks.
>
>> diff --git a/tools/arch/powerpc/include/uapi/asm/perf_regs.h b/tools/arch/powerpc/include/uapi/asm/perf_regs.h
>> index f599064..485b1d5 100644
>> --- a/tools/arch/powerpc/include/uapi/asm/perf_regs.h
>> +++ b/tools/arch/powerpc/include/uapi/asm/perf_regs.h
>> @@ -48,6 +48,18 @@ enum perf_event_powerpc_regs {
>> PERF_REG_POWERPC_DSISR,
>> PERF_REG_POWERPC_SIER,
>> PERF_REG_POWERPC_MMCRA,
>> - PERF_REG_POWERPC_MAX,
>> + /* Extended registers */
>> + PERF_REG_POWERPC_MMCR0,
>> + PERF_REG_POWERPC_MMCR1,
>> + PERF_REG_POWERPC_MMCR2,
>> + /* Max regs without the extended regs */
>> + PERF_REG_POWERPC_MAX = PERF_REG_POWERPC_MMCRA + 1,
>
> I don't really understand this idea of a max that's not the max.
Hi Michael
This is the MAX without extended regs. This is mainly used in `arch/powerpc/perf/perf_regs.c` to define pt_regs_offset ( to get index
for other regs ) and also is used to determine whether requested register is an extended reg while capturing data in sample
( in `perf_reg_value` )
Thanks
Athira
>
>> };
>> +
>> +#define PERF_REG_PMU_MASK ((1ULL << PERF_REG_POWERPC_MAX) - 1)
>> +
>> +/* PERF_REG_EXTENDED_MASK value for CPU_FTR_ARCH_300 */
>> +#define PERF_REG_PMU_MASK_300 (((1ULL << (PERF_REG_POWERPC_MMCR2 + 1)) - 1) \
>> + - PERF_REG_PMU_MASK)
>> +
>> #endif /* _UAPI_ASM_POWERPC_PERF_REGS_H */
>> diff --git a/tools/perf/arch/powerpc/include/perf_regs.h b/tools/perf/arch/powerpc/include/perf_regs.h
>> index e18a355..46ed00d 100644
>> --- a/tools/perf/arch/powerpc/include/perf_regs.h
>> +++ b/tools/perf/arch/powerpc/include/perf_regs.h
>> @@ -64,7 +64,10 @@
>> [PERF_REG_POWERPC_DAR] = "dar",
>> [PERF_REG_POWERPC_DSISR] = "dsisr",
>> [PERF_REG_POWERPC_SIER] = "sier",
>> - [PERF_REG_POWERPC_MMCRA] = "mmcra"
>> + [PERF_REG_POWERPC_MMCRA] = "mmcra",
>> + [PERF_REG_POWERPC_MMCR0] = "mmcr0",
>> + [PERF_REG_POWERPC_MMCR1] = "mmcr1",
>> + [PERF_REG_POWERPC_MMCR2] = "mmcr2",
>> };
>>
>> static inline const char *perf_reg_name(int id)
>> diff --git a/tools/perf/arch/powerpc/util/perf_regs.c b/tools/perf/arch/powerpc/util/perf_regs.c
>> index 0a52429..9179230 100644
>> --- a/tools/perf/arch/powerpc/util/perf_regs.c
>> +++ b/tools/perf/arch/powerpc/util/perf_regs.c
>> @@ -6,9 +6,14 @@
>>
>> #include "../../../util/perf_regs.h"
>> #include "../../../util/debug.h"
>> +#include "../../../util/event.h"
>> +#include "../../../util/header.h"
>> +#include "../../../perf-sys.h"
>>
>> #include <linux/kernel.h>
>>
>> +#define PVR_POWER9 0x004E
>> +
>> const struct sample_reg sample_reg_masks[] = {
>> SMPL_REG(r0, PERF_REG_POWERPC_R0),
>> SMPL_REG(r1, PERF_REG_POWERPC_R1),
>> @@ -55,6 +60,9 @@
>> SMPL_REG(dsisr, PERF_REG_POWERPC_DSISR),
>> SMPL_REG(sier, PERF_REG_POWERPC_SIER),
>> SMPL_REG(mmcra, PERF_REG_POWERPC_MMCRA),
>> + SMPL_REG(mmcr0, PERF_REG_POWERPC_MMCR0),
>> + SMPL_REG(mmcr1, PERF_REG_POWERPC_MMCR1),
>> + SMPL_REG(mmcr2, PERF_REG_POWERPC_MMCR2),
>> SMPL_REG_END
>> };
>>
>> @@ -163,3 +171,50 @@ int arch_sdt_arg_parse_op(char *old_op, char **new_op)
>>
>> return SDT_ARG_VALID;
>> }
>> +
>> +uint64_t arch__intr_reg_mask(void)
>> +{
>> + struct perf_event_attr attr = {
>> + .type = PERF_TYPE_HARDWARE,
>> + .config = PERF_COUNT_HW_CPU_CYCLES,
>> + .sample_type = PERF_SAMPLE_REGS_INTR,
>> + .precise_ip = 1,
>> + .disabled = 1,
>> + .exclude_kernel = 1,
>> + };
>> + int fd, ret;
>> + char buffer[64];
>> + u32 version;
>> + u64 extended_mask = 0;
>> +
>> + /* Get the PVR value to set the extended
>> + * mask specific to platform
>
> Comment format is wrong, and punctuation please.
>
>> + */
>> + get_cpuid(buffer, sizeof(buffer));
>> + ret = sscanf(buffer, "%u,", &version);
>
> This is powerpc specific code, why not just use mfspr(SPRN_PVR), rather
> than redirecting via printf/sscanf.
>
>> +
>> + if (ret != 1) {
>> + pr_debug("Failed to get the processor version, unable to output extended registers\n");
>> + return PERF_REGS_MASK;
>> + }
>> +
>> + if (version == PVR_POWER9)
>> + extended_mask = PERF_REG_PMU_MASK_300;
>> + else
>> + return PERF_REGS_MASK;
>> +
>> + attr.sample_regs_intr = extended_mask;
>> + attr.sample_period = 1;
>> + event_attr_init(&attr);
>> +
>> + /*
>> + * check if the pmu supports perf extended regs, before
>> + * returning the register mask to sample.
>> + */
>> + fd = sys_perf_event_open(&attr, 0, -1, -1, 0);
>> + if (fd != -1) {
>> + close(fd);
>> + return (extended_mask | PERF_REGS_MASK);
>> + }
>> + return PERF_REGS_MASK;
>
> I think this would read a bit better like:
>
> mask = PERF_REGS_MASK;
>
> if (version == PVR_POWER9)
> extended_mask = PERF_REG_PMU_MASK_300;
> else
> return mask;
>
> attr.sample_regs_intr = extended_mask;
> attr.sample_period = 1;
> event_attr_init(&attr);
>
> /*
> * check if the pmu supports perf extended regs, before
> * returning the register mask to sample.
> */
> fd = sys_perf_event_open(&attr, 0, -1, -1, 0);
> if (fd != -1) {
> close(fd);
> mask |= extended_mask;
> }
>
> return mask;
>
>
> cheers
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^ permalink raw reply
* [PATCH] powerpc/book3s64/pkeys: Fix pkey_access_permitted w.r.t execute disable pkey
From: Aneesh Kumar K.V @ 2020-07-12 13:20 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, Sandipan Das
Even if the IAMR value deny the execute access, current kernel return true
w.r.t pkey_access_permitted() for execute permission check if the AMR
read pkey bit is cleared.
This results in repeated page fault loop with a test like below.
#define _GNU_SOURCE
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <inttypes.h>
#include <assert.h>
#include <malloc.h>
#include <unistd.h>
#include <pthread.h>
#include <sys/mman.h>
#ifdef SYS_pkey_mprotect
#undef SYS_pkey_mprotect
#endif
#ifdef SYS_pkey_alloc
#undef SYS_pkey_alloc
#endif
#ifdef SYS_pkey_free
#undef SYS_pkey_free
#endif
#undef PKEY_DISABLE_EXECUTE
#define PKEY_DISABLE_EXECUTE 0x4
#define SYS_pkey_mprotect 386
#define SYS_pkey_alloc 384
#define SYS_pkey_free 385
#define PPC_INST_NOP 0x60000000
#define PPC_INST_BLR 0x4e800020
#define PROT_RWX (PROT_READ | PROT_WRITE | PROT_EXEC)
static int sys_pkey_mprotect(void *addr, size_t len, int prot, int pkey)
{
return syscall(SYS_pkey_mprotect, addr, len, prot, pkey);
}
static int sys_pkey_alloc(unsigned long flags, unsigned long access_rights)
{
return syscall(SYS_pkey_alloc, flags, access_rights);
}
static int sys_pkey_free(int pkey)
{
return syscall(SYS_pkey_free, pkey);
}
static void do_execute(void *region)
{
/* jump to region */
asm volatile(
"mtctr %0;"
"bctrl"
: : "r"(region) : "ctr", "lr");
}
static void do_protect(void *region)
{
size_t pgsize;
int i, pkey;
pgsize = getpagesize();
pkey = sys_pkey_alloc(0, PKEY_DISABLE_EXECUTE);
assert (pkey > 0);
/* perform mprotect */
assert(!sys_pkey_mprotect(region, pgsize, PROT_RWX, pkey));
do_execute(region);
/* free pkey */
assert(!sys_pkey_free(pkey));
}
int main(int argc, char **argv)
{
size_t pgsize, numinsns;
unsigned int *region;
int i;
/* allocate memory region to protect */
pgsize = getpagesize();
region = memalign(pgsize, pgsize);
assert(region != NULL);
assert(!mprotect(region, pgsize, PROT_RWX));
/* fill page with NOPs with a BLR at the end */
numinsns = pgsize / sizeof(region[0]);
for (i = 0; i < numinsns - 1; i++)
region[i] = PPC_INST_NOP;
region[i] = PPC_INST_BLR;
do_protect(region);
return EXIT_SUCCESS;
}
Fixes: f2407ef3ba22 ("powerpc: helper to validate key-access permissions of a pte")
Reported-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/mm/book3s64/pkeys.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index ca5fcb4bff32..d174106bab67 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -354,12 +354,14 @@ static bool pkey_access_permitted(int pkey, bool write, bool execute)
u64 amr;
pkey_shift = pkeyshift(pkey);
- if (execute && !(read_iamr() & (IAMR_EX_BIT << pkey_shift)))
- return true;
+ if (execute)
+ return !(read_iamr() & (IAMR_EX_BIT << pkey_shift));
+
+ amr = read_amr();
+ if (write)
+ return !(amr & (AMR_WR_BIT << pkey_shift));
- amr = read_amr(); /* Delay reading amr until absolutely needed */
- return ((!write && !(amr & (AMR_RD_BIT << pkey_shift))) ||
- (write && !(amr & (AMR_WR_BIT << pkey_shift))));
+ return !(amr & (AMR_RD_BIT << pkey_shift));
}
bool arch_pte_access_permitted(u64 pte, bool write, bool execute)
--
2.26.2
^ permalink raw reply related
* Re: [GIT PULL] Please pull powerpc/linux.git powerpc-5.8-6 tag
From: pr-tracker-bot @ 2020-07-11 18:25 UTC (permalink / raw)
To: Michael Ellerman; +Cc: linuxppc-dev, Linus Torvalds, linux-kernel, npiggin
In-Reply-To: <87v9iuuv7n.fsf@mpe.ellerman.id.au>
The pull request you sent on Sat, 11 Jul 2020 21:50:20 +1000:
> https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git tags/powerpc-5.8-6
has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/997c4431f04d8f0d6063bac3bcdceba8d939b879
Thank you!
--
Deet-doot-dot, I am a bot.
https://korg.wiki.kernel.org/userdoc/prtracker
^ permalink raw reply
* [GIT PULL] Please pull powerpc/linux.git powerpc-5.8-6 tag
From: Michael Ellerman @ 2020-07-11 11:50 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linuxppc-dev, linux-kernel, npiggin
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
Hi Linus,
Please pull another powerpc fix for 5.8:
The following changes since commit 19ab500edb5d6020010caba48ce3b4ce4182ab63:
powerpc/mm/pkeys: Make pkey access check work on execute_only_key (2020-06-29 16:17:02 +1000)
are available in the git repository at:
https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git tags/powerpc-5.8-6
for you to fetch changes up to 4557ac6b344b8cdf948ff8b007e8e1de34832f2e:
powerpc/64s/exception: Fix 0x1500 interrupt handler crash (2020-07-08 20:41:06 +1000)
- ------------------------------------------------------------------
powerpc fixes for 5.8 #6
One fix for a crash/soft lockup on Power8, caused by the exception rework we did
in v5.7.
Thanks to:
Paul Menzel, Nicholas Piggin.
- ------------------------------------------------------------------
Nicholas Piggin (1):
powerpc/64s/exception: Fix 0x1500 interrupt handler crash
arch/powerpc/kernel/exceptions-64s.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
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^ permalink raw reply
* Re: [PATCH 11/20] Documentation: leds/ledtrig-transient: eliminate duplicated word
From: Pavel Machek @ 2020-07-11 9:35 UTC (permalink / raw)
To: Randy Dunlap
Cc: kvm, linux-doc, David Airlie, kgdb-bugreport, linux-fpga,
Liviu Dudau, dri-devel, Douglas Anderson, Paul Cercueil, keyrings,
Paul Mackerras, linux-i2c, Srinivas Pandruvada, Mihail Atanassov,
linux-leds, linux-s390, Daniel Thompson, linux-scsi,
Jonathan Corbet, Masahiro Yamada, Matthew Wilcox, Halil Pasic,
Jarkko Sakkinen, James Wang, linux-input, Mali DP Maintainers,
Derek Kiernan, linux-mips, Dragan Cvetic, Wu Hao, Tony Krowiak,
linux-kbuild, James E.J. Bottomley, Jiri Kosina, Hannes Reinecke,
linux-block, Thomas Bogendoerfer, Jacek Anaszewski, linux-mm,
Dan Williams, Andrew Morton, Mimi Zohar, Jens Axboe, Michal Marek,
Martin K. Petersen, Pierre Morel, linux-kernel, Wolfram Sang,
Daniel Vetter, Jason Wessel, Paolo Bonzini, linux-integrity,
linuxppc-dev, Mike Rapoport, Dan Murphy
In-Reply-To: <20200707180414.10467-12-rdunlap@infradead.org>
[-- Attachment #1: Type: text/plain, Size: 502 bytes --]
On Tue 2020-07-07 11:04:05, Randy Dunlap wrote:
> Drop the doubled word "for".
>
> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: linux-doc@vger.kernel.org
> Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
(I expect documentation people take this, not me).
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
[-- Attachment #2: Digital signature --]
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^ permalink raw reply
* [v3 4/5] KVM: PPC: Book3S HV: retry page migration before erroring-out H_SVM_PAGE_IN
From: Ram Pai @ 2020-07-11 9:13 UTC (permalink / raw)
To: kvm-ppc, linuxppc-dev
Cc: ldufour, linuxram, cclaudio, bharata, sathnaga, aneesh.kumar,
sukadev, bauerman, david
In-Reply-To: <1594458827-31866-1-git-send-email-linuxram@us.ibm.com>
The page requested for page-in; sometimes, can have transient
references, and hence cannot migrate immediately. Retry a few times
before returning error.
H_SVM_PAGE_IN interface is enhanced to return H_BUSY if the page is
not in a migratable state.
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Claudio Carvalho <cclaudio@linux.ibm.com>
Cc: kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
Documentation/powerpc/ultravisor.rst | 1 +
arch/powerpc/kvm/book3s_hv_uvmem.c | 54 +++++++++++++++++++++---------------
2 files changed, 33 insertions(+), 22 deletions(-)
diff --git a/Documentation/powerpc/ultravisor.rst b/Documentation/powerpc/ultravisor.rst
index d98fc85..638d1a7 100644
--- a/Documentation/powerpc/ultravisor.rst
+++ b/Documentation/powerpc/ultravisor.rst
@@ -1034,6 +1034,7 @@ Return values
* H_PARAMETER if ``guest_pa`` is invalid.
* H_P2 if ``flags`` is invalid.
* H_P3 if ``order`` of page is invalid.
+ * H_BUSY if ``page`` is not in a state to pagein
Description
~~~~~~~~~~~
diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
index 12ed52a..c9bdef6 100644
--- a/arch/powerpc/kvm/book3s_hv_uvmem.c
+++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
@@ -843,7 +843,7 @@ unsigned long kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa,
struct vm_area_struct *vma;
int srcu_idx;
unsigned long gfn = gpa >> page_shift;
- int ret;
+ int ret, repeat_count = REPEAT_COUNT;
if (!(kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START))
return H_UNSUPPORTED;
@@ -857,34 +857,44 @@ unsigned long kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa,
if (flags & H_PAGE_IN_SHARED)
return kvmppc_share_page(kvm, gpa, page_shift);
- ret = H_PARAMETER;
srcu_idx = srcu_read_lock(&kvm->srcu);
- down_write(&kvm->mm->mmap_sem);
- start = gfn_to_hva(kvm, gfn);
- if (kvm_is_error_hva(start))
- goto out;
-
- mutex_lock(&kvm->arch.uvmem_lock);
/* Fail the page-in request of an already paged-in page */
- if (kvmppc_gfn_is_uvmem_pfn(gfn, kvm, NULL))
- goto out_unlock;
+ mutex_lock(&kvm->arch.uvmem_lock);
+ ret = kvmppc_gfn_is_uvmem_pfn(gfn, kvm, NULL);
+ mutex_unlock(&kvm->arch.uvmem_lock);
+ if (ret) {
+ srcu_read_unlock(&kvm->srcu, srcu_idx);
+ return H_PARAMETER;
+ }
- end = start + (1UL << page_shift);
- vma = find_vma_intersection(kvm->mm, start, end);
- if (!vma || vma->vm_start > start || vma->vm_end < end)
- goto out_unlock;
+ do {
+ ret = H_PARAMETER;
+ down_write(&kvm->mm->mmap_sem);
- if (kvmppc_svm_migrate_page(vma, start, end, gpa, kvm, page_shift,
- true))
- goto out_unlock;
+ start = gfn_to_hva(kvm, gfn);
+ if (kvm_is_error_hva(start)) {
+ up_write(&kvm->mm->mmap_sem);
+ break;
+ }
- ret = H_SUCCESS;
+ end = start + (1UL << page_shift);
+ vma = find_vma_intersection(kvm->mm, start, end);
+ if (!vma || vma->vm_start > start || vma->vm_end < end) {
+ up_write(&kvm->mm->mmap_sem);
+ break;
+ }
+
+ mutex_lock(&kvm->arch.uvmem_lock);
+ ret = kvmppc_svm_migrate_page(vma, start, end, gpa, kvm, page_shift, true);
+ mutex_unlock(&kvm->arch.uvmem_lock);
+
+ up_write(&kvm->mm->mmap_sem);
+ } while (ret == -2 && repeat_count--);
+
+ if (ret == -2)
+ ret = H_BUSY;
-out_unlock:
- mutex_unlock(&kvm->arch.uvmem_lock);
-out:
- up_write(&kvm->mm->mmap_sem);
srcu_read_unlock(&kvm->srcu, srcu_idx);
return ret;
}
--
1.8.3.1
^ permalink raw reply related
* [v3 0/5] Migrate non-migrated pages of a SVM.
From: Ram Pai @ 2020-07-11 9:13 UTC (permalink / raw)
To: kvm-ppc, linuxppc-dev
Cc: ldufour, linuxram, cclaudio, bharata, sathnaga, aneesh.kumar,
sukadev, bauerman, david
The time taken to switch a VM to Secure-VM, increases by the size of the VM. A
100GB VM takes about 7minutes. This is unacceptable. This linear increase is
caused by a suboptimal behavior by the Ultravisor and the Hypervisor. The
Ultravisor unnecessarily migrates all the GFN of the VM from normal-memory to
secure-memory. It has to just migrate the necessary and sufficient GFNs.
However when the optimization is incorporated in the Ultravisor, the Hypervisor
starts misbehaving. The Hypervisor has a inbuilt assumption that the Ultravisor
will explicitly request to migrate, each and every GFN of the VM. If only
necessary and sufficient GFNs are requested for migration, the Hypervisor
continues to manage the remaining GFNs as normal GFNs. This leads of memory
corruption, manifested consistently when the SVM reboots.
The same is true, when a memory slot is hotplugged into a SVM. The Hypervisor
expects the ultravisor to request migration of all GFNs to secure-GFN. But the
hypervisor cannot handle any H_SVM_PAGE_IN requests from the Ultravisor, done
in the context of UV_REGISTER_MEM_SLOT ucall. This problem manifests as random
errors in the SVM, when a memory-slot is hotplugged.
This patch series automatically migrates the non-migrated pages of a SVM,
and thus solves the problem.
Testing: Passed rigorous testing using various sized SVMs.
Changelog:
v3: . Optimized the page-migration retry-logic.
. Relax and relinquish the cpu regularly while bulk migrating
the non-migrated pages. This issue was causing soft-lockups.
Fixed it.
. Added a new patch, to retry page-migration a couple of times
before returning H_BUSY in H_SVM_PAGE_IN. This issue was
seen a few times in a 24hour continuous reboot test of the SVMs.
v2: . fixed a bug observed by Laurent. The state of the GFN's associated
with Secure-VMs were not reset during memslot flush.
. Re-organized the code, for easier review.
. Better description of the patch series.
v1: fixed a bug observed by Bharata. Pages that where paged-in and later
paged-out must also be skipped from migration during H_SVM_INIT_DONE.
Laurent Dufour (1):
KVM: PPC: Book3S HV: migrate hot plugged memory
Ram Pai (4):
KVM: PPC: Book3S HV: Disable page merging in H_SVM_INIT_START
KVM: PPC: Book3S HV: track the state GFNs associated with secure VMs
KVM: PPC: Book3S HV: migrate remaining normal-GFNs to secure-GFNs in
H_SVM_INIT_DONE
KVM: PPC: Book3S HV: retry page migration before erroring-out
H_SVM_PAGE_IN
Documentation/powerpc/ultravisor.rst | 3 +
arch/powerpc/include/asm/kvm_book3s_uvmem.h | 2 +
arch/powerpc/kvm/book3s_hv.c | 10 +-
arch/powerpc/kvm/book3s_hv_uvmem.c | 487 ++++++++++++++++++++++++----
4 files changed, 429 insertions(+), 73 deletions(-)
--
1.8.3.1
^ permalink raw reply
* [v3 5/5] KVM: PPC: Book3S HV: migrate hot plugged memory
From: Ram Pai @ 2020-07-11 9:13 UTC (permalink / raw)
To: kvm-ppc, linuxppc-dev
Cc: ldufour, linuxram, cclaudio, bharata, sathnaga, aneesh.kumar,
sukadev, bauerman, david
In-Reply-To: <1594458827-31866-1-git-send-email-linuxram@us.ibm.com>
From: Laurent Dufour <ldufour@linux.ibm.com>
When a memory slot is hot plugged to a SVM, PFNs associated with the
GFNs in that slot must be migrated to the secure-PFNs, aka device-PFNs.
kvmppc_uv_migrate_mem_slot() is called to accomplish this. UV_PAGE_IN
ucall is skipped, since the ultravisor does not trust the content of
those pages and hence ignores it.
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[resolved conflicts, and modified the commit log]
---
arch/powerpc/kvm/book3s_hv.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 819f96d..b0d4231 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4523,10 +4523,12 @@ static void kvmppc_core_commit_memory_region_hv(struct kvm *kvm,
case KVM_MR_CREATE:
if (kvmppc_uvmem_slot_init(kvm, new))
return;
- uv_register_mem_slot(kvm->arch.lpid,
- new->base_gfn << PAGE_SHIFT,
- new->npages * PAGE_SIZE,
- 0, new->id);
+ if (uv_register_mem_slot(kvm->arch.lpid,
+ new->base_gfn << PAGE_SHIFT,
+ new->npages * PAGE_SIZE,
+ 0, new->id))
+ return;
+ kvmppc_uv_migrate_mem_slot(kvm, new);
break;
case KVM_MR_DELETE:
uv_unregister_mem_slot(kvm->arch.lpid, old->id);
--
1.8.3.1
^ permalink raw reply related
* [v3 3/5] KVM: PPC: Book3S HV: migrate remaining normal-GFNs to secure-GFNs in H_SVM_INIT_DONE
From: Ram Pai @ 2020-07-11 9:13 UTC (permalink / raw)
To: kvm-ppc, linuxppc-dev
Cc: ldufour, linuxram, cclaudio, bharata, sathnaga, aneesh.kumar,
sukadev, bauerman, david
In-Reply-To: <1594458827-31866-1-git-send-email-linuxram@us.ibm.com>
The Ultravisor is expected to explicitly call H_SVM_PAGE_IN for all the pages
of the SVM before calling H_SVM_INIT_DONE. This causes a huge delay in
tranistioning the VM to SVM. The Ultravisor is interested in the pages that
contain the kernel, initrd and other important data structures. The rest of the
pages contain throw-away content. Hence requesting just the necessary and
sufficient pages from the Hypervisor is sufficient.
However if not all pages are requested by the Ultravisor, the Hypervisor
continues to consider the GFNs corresponding to the non-requested pages as
normal GFNs. This can lead to data-corruption and undefined behavior.
Move all the PFNs associated with the SVM's GFNs to secure-PFNs, in
H_SVM_INIT_DONE. Skip the GFNs that are already Paged-in or Shared or
Paged-in followed by a Paged-out.
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Claudio Carvalho <cclaudio@linux.ibm.com>
Cc: kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
Documentation/powerpc/ultravisor.rst | 2 +
arch/powerpc/include/asm/kvm_book3s_uvmem.h | 2 +
arch/powerpc/kvm/book3s_hv_uvmem.c | 166 +++++++++++++++++++++++++---
3 files changed, 156 insertions(+), 14 deletions(-)
diff --git a/Documentation/powerpc/ultravisor.rst b/Documentation/powerpc/ultravisor.rst
index df136c8..d98fc85 100644
--- a/Documentation/powerpc/ultravisor.rst
+++ b/Documentation/powerpc/ultravisor.rst
@@ -933,6 +933,8 @@ Return values
* H_UNSUPPORTED if called from the wrong context (e.g.
from an SVM or before an H_SVM_INIT_START
hypercall).
+ * H_STATE if the hypervisor could not successfully
+ transition the VM to Secure VM.
Description
~~~~~~~~~~~
diff --git a/arch/powerpc/include/asm/kvm_book3s_uvmem.h b/arch/powerpc/include/asm/kvm_book3s_uvmem.h
index 9cb7d8b..f229ab5 100644
--- a/arch/powerpc/include/asm/kvm_book3s_uvmem.h
+++ b/arch/powerpc/include/asm/kvm_book3s_uvmem.h
@@ -23,6 +23,8 @@ unsigned long kvmppc_h_svm_page_out(struct kvm *kvm,
unsigned long kvmppc_h_svm_init_abort(struct kvm *kvm);
void kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free,
struct kvm *kvm, bool skip_page_out);
+int kvmppc_uv_migrate_mem_slot(struct kvm *kvm,
+ const struct kvm_memory_slot *memslot);
#else
static inline int kvmppc_uvmem_init(void)
{
diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
index 6d6c256..12ed52a 100644
--- a/arch/powerpc/kvm/book3s_hv_uvmem.c
+++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
@@ -93,6 +93,7 @@
#include <asm/ultravisor.h>
#include <asm/mman.h>
#include <asm/kvm_ppc.h>
+#include <asm/kvm_book3s_uvmem.h>
static struct dev_pagemap kvmppc_uvmem_pgmap;
static unsigned long *kvmppc_uvmem_bitmap;
@@ -348,6 +349,43 @@ static bool kvmppc_gfn_is_uvmem_pfn(unsigned long gfn, struct kvm *kvm,
return false;
}
+/*
+ * starting from *gfn search for the next available GFN that is not yet
+ * transitioned to a secure GFN. return the value of that GFN in *gfn. If a
+ * GFN is found, return true, else return false
+ */
+static bool kvmppc_next_nontransitioned_gfn(const struct kvm_memory_slot *memslot,
+ struct kvm *kvm, unsigned long *gfn)
+{
+ struct kvmppc_uvmem_slot *p;
+ bool ret = false;
+ unsigned long i;
+
+ mutex_lock(&kvm->arch.uvmem_lock);
+
+ list_for_each_entry(p, &kvm->arch.uvmem_pfns, list)
+ if (*gfn >= p->base_pfn && *gfn < p->base_pfn + p->nr_pfns)
+ break;
+ if (!p)
+ goto out;
+ /*
+ * The code below assumes, one to one correspondence between
+ * kvmppc_uvmem_slot and memslot.
+ */
+ for (i = *gfn; i < p->base_pfn + p->nr_pfns; i++) {
+ unsigned long index = i - p->base_pfn;
+
+ if (!(p->pfns[index] & KVMPPC_GFN_FLAG_MASK)) {
+ *gfn = i;
+ ret = true;
+ break;
+ }
+ }
+out:
+ mutex_unlock(&kvm->arch.uvmem_lock);
+ return ret;
+}
+
static int kvmppc_memslot_page_merge(struct kvm *kvm,
struct kvm_memory_slot *memslot, bool merge)
{
@@ -461,12 +499,31 @@ unsigned long kvmppc_h_svm_init_start(struct kvm *kvm)
unsigned long kvmppc_h_svm_init_done(struct kvm *kvm)
{
+ struct kvm_memslots *slots;
+ struct kvm_memory_slot *memslot;
+ int srcu_idx;
+ long ret = H_SUCCESS;
+
if (!(kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START))
return H_UNSUPPORTED;
+ /* migrate any unmoved normal pfn to device pfns*/
+ srcu_idx = srcu_read_lock(&kvm->srcu);
+ slots = kvm_memslots(kvm);
+ kvm_for_each_memslot(memslot, slots) {
+ ret = kvmppc_uv_migrate_mem_slot(kvm, memslot);
+ if (ret) {
+ ret = H_STATE;
+ goto out;
+ }
+ }
+
kvm->arch.secure_guest |= KVMPPC_SECURE_INIT_DONE;
pr_info("LPID %d went secure\n", kvm->arch.lpid);
- return H_SUCCESS;
+
+out:
+ srcu_read_unlock(&kvm->srcu, srcu_idx);
+ return ret;
}
/*
@@ -587,12 +644,14 @@ static struct page *kvmppc_uvmem_get_page(unsigned long gpa, struct kvm *kvm)
}
/*
- * Alloc a PFN from private device memory pool and copy page from normal
- * memory to secure memory using UV_PAGE_IN uvcall.
+ * Alloc a PFN from private device memory pool. If @pagein is true,
+ * copy page from normal memory to secure memory using UV_PAGE_IN uvcall.
*/
-static int kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start,
- unsigned long end, unsigned long gpa, struct kvm *kvm,
- unsigned long page_shift)
+static int kvmppc_svm_migrate_page(struct vm_area_struct *vma,
+ unsigned long start,
+ unsigned long end, unsigned long gpa, struct kvm *kvm,
+ unsigned long page_shift,
+ bool pagein)
{
unsigned long src_pfn, dst_pfn = 0;
struct migrate_vma mig;
@@ -613,7 +672,7 @@ static int kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start,
return ret;
if (!(*mig.src & MIGRATE_PFN_MIGRATE)) {
- ret = -1;
+ ret = -2;
goto out_finalize;
}
@@ -623,11 +682,16 @@ static int kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start,
goto out_finalize;
}
- pfn = *mig.src >> MIGRATE_PFN_SHIFT;
- spage = migrate_pfn_to_page(*mig.src);
- if (spage)
- uv_page_in(kvm->arch.lpid, pfn << page_shift, gpa, 0,
- page_shift);
+ if (pagein) {
+ pfn = *mig.src >> MIGRATE_PFN_SHIFT;
+ spage = migrate_pfn_to_page(*mig.src);
+ if (spage) {
+ ret = uv_page_in(kvm->arch.lpid, pfn << page_shift,
+ gpa, 0, page_shift);
+ if (ret)
+ goto out_finalize;
+ }
+ }
*mig.dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
migrate_vma_pages(&mig);
@@ -637,6 +701,77 @@ static int kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start,
}
/*
+ * return 1, if some page migration failed because of transient error,
+ * while the remaining pages migrated successfully.
+ * The caller can use this as a hint to retry.
+ *
+ * return 0 otherwise. *ret indicates the success status
+ * of this call.
+ */
+static int __kvmppc_uv_migrate_mem_slot(struct kvm *kvm,
+ const struct kvm_memory_slot *memslot, int *ret)
+{
+ unsigned long gfn = memslot->base_gfn;
+ struct vm_area_struct *vma;
+ unsigned long start, end;
+ bool retry = 0;
+
+ *ret = 0;
+ while (kvmppc_next_nontransitioned_gfn(memslot, kvm, &gfn)) {
+
+ down_write(&kvm->mm->mmap_sem);
+ start = gfn_to_hva(kvm, gfn);
+ if (kvm_is_error_hva(start)) {
+ *ret = H_STATE;
+ goto next;
+ }
+
+ end = start + (1UL << PAGE_SHIFT);
+ vma = find_vma_intersection(kvm->mm, start, end);
+ if (!vma || vma->vm_start > start || vma->vm_end < end) {
+ *ret = H_STATE;
+ goto next;
+ }
+
+ mutex_lock(&kvm->arch.uvmem_lock);
+ *ret = kvmppc_svm_migrate_page(vma, start, end,
+ (gfn << PAGE_SHIFT), kvm, PAGE_SHIFT, false);
+ mutex_unlock(&kvm->arch.uvmem_lock);
+
+next:
+ up_write(&kvm->mm->mmap_sem);
+
+ if (*ret == -2) {
+ retry = 1;
+ continue;
+ }
+
+ if (*ret)
+ return 0;
+ }
+ return retry;
+}
+
+#define REPEAT_COUNT 10
+
+int kvmppc_uv_migrate_mem_slot(struct kvm *kvm,
+ const struct kvm_memory_slot *memslot)
+{
+ int ret = 0, repeat_count = REPEAT_COUNT;
+
+ /*
+ * try migration of pages in the memslot 'repeat_count' number of
+ * times, provided each time migration fails because of transient
+ * errors only.
+ */
+ while (__kvmppc_uv_migrate_mem_slot(kvm, memslot, &ret) &&
+ repeat_count--)
+ ;
+
+ return ret;
+}
+
+/*
* Shares the page with HV, thus making it a normal page.
*
* - If the page is already secure, then provision a new page and share
@@ -740,8 +875,11 @@ unsigned long kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa,
if (!vma || vma->vm_start > start || vma->vm_end < end)
goto out_unlock;
- if (!kvmppc_svm_page_in(vma, start, end, gpa, kvm, page_shift))
- ret = H_SUCCESS;
+ if (kvmppc_svm_migrate_page(vma, start, end, gpa, kvm, page_shift,
+ true))
+ goto out_unlock;
+
+ ret = H_SUCCESS;
out_unlock:
mutex_unlock(&kvm->arch.uvmem_lock);
--
1.8.3.1
^ permalink raw reply related
* [v3 1/5] KVM: PPC: Book3S HV: Disable page merging in H_SVM_INIT_START
From: Ram Pai @ 2020-07-11 9:13 UTC (permalink / raw)
To: kvm-ppc, linuxppc-dev
Cc: ldufour, linuxram, cclaudio, bharata, sathnaga, aneesh.kumar,
sukadev, bauerman, david
In-Reply-To: <1594458827-31866-1-git-send-email-linuxram@us.ibm.com>
Merging of pages associated with each memslot of a SVM is
disabled the page is migrated in H_SVM_PAGE_IN handler.
This operation should have been done much earlier; the moment the VM
is initiated for secure-transition. Delaying this operation, increases
the probability for those pages to acquire new references , making it
impossible to migrate those pages in H_SVM_PAGE_IN handler.
Disable page-migration in H_SVM_INIT_START handling.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
arch/powerpc/kvm/book3s_hv_uvmem.c | 96 +++++++++++++++++++++++++++++---------
1 file changed, 74 insertions(+), 22 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
index 3d987b1..bfc3841 100644
--- a/arch/powerpc/kvm/book3s_hv_uvmem.c
+++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
@@ -211,6 +211,65 @@ static bool kvmppc_gfn_is_uvmem_pfn(unsigned long gfn, struct kvm *kvm,
return false;
}
+static int kvmppc_memslot_page_merge(struct kvm *kvm,
+ struct kvm_memory_slot *memslot, bool merge)
+{
+ unsigned long gfn = memslot->base_gfn;
+ unsigned long end, start = gfn_to_hva(kvm, gfn);
+ int ret = 0;
+ struct vm_area_struct *vma;
+ int merge_flag = (merge) ? MADV_MERGEABLE : MADV_UNMERGEABLE;
+
+ if (kvm_is_error_hva(start))
+ return H_STATE;
+
+ end = start + (memslot->npages << PAGE_SHIFT);
+
+ down_write(&kvm->mm->mmap_sem);
+ do {
+ vma = find_vma_intersection(kvm->mm, start, end);
+ if (!vma) {
+ ret = H_STATE;
+ break;
+ }
+ ret = ksm_madvise(vma, vma->vm_start, vma->vm_end,
+ merge_flag, &vma->vm_flags);
+ if (ret) {
+ ret = H_STATE;
+ break;
+ }
+ start = vma->vm_end + 1;
+ } while (end > vma->vm_end);
+
+ up_write(&kvm->mm->mmap_sem);
+ return ret;
+}
+
+static int __kvmppc_page_merge(struct kvm *kvm, bool merge)
+{
+ struct kvm_memslots *slots;
+ struct kvm_memory_slot *memslot;
+ int ret = 0;
+
+ slots = kvm_memslots(kvm);
+ kvm_for_each_memslot(memslot, slots) {
+ ret = kvmppc_memslot_page_merge(kvm, memslot, merge);
+ if (ret)
+ break;
+ }
+ return ret;
+}
+
+static inline int kvmppc_disable_page_merge(struct kvm *kvm)
+{
+ return __kvmppc_page_merge(kvm, false);
+}
+
+static inline int kvmppc_enable_page_merge(struct kvm *kvm)
+{
+ return __kvmppc_page_merge(kvm, true);
+}
+
unsigned long kvmppc_h_svm_init_start(struct kvm *kvm)
{
struct kvm_memslots *slots;
@@ -232,11 +291,18 @@ unsigned long kvmppc_h_svm_init_start(struct kvm *kvm)
return H_AUTHORITY;
srcu_idx = srcu_read_lock(&kvm->srcu);
+
+ /* disable page-merging for all memslot */
+ ret = kvmppc_disable_page_merge(kvm);
+ if (ret)
+ goto out;
+
+ /* register the memslot */
slots = kvm_memslots(kvm);
kvm_for_each_memslot(memslot, slots) {
if (kvmppc_uvmem_slot_init(kvm, memslot)) {
ret = H_PARAMETER;
- goto out;
+ break;
}
ret = uv_register_mem_slot(kvm->arch.lpid,
memslot->base_gfn << PAGE_SHIFT,
@@ -245,9 +311,12 @@ unsigned long kvmppc_h_svm_init_start(struct kvm *kvm)
if (ret < 0) {
kvmppc_uvmem_slot_free(kvm, memslot);
ret = H_PARAMETER;
- goto out;
+ break;
}
}
+
+ if (ret)
+ kvmppc_enable_page_merge(kvm);
out:
srcu_read_unlock(&kvm->srcu, srcu_idx);
return ret;
@@ -384,7 +453,7 @@ static struct page *kvmppc_uvmem_get_page(unsigned long gpa, struct kvm *kvm)
*/
static int kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start,
unsigned long end, unsigned long gpa, struct kvm *kvm,
- unsigned long page_shift, bool *downgrade)
+ unsigned long page_shift)
{
unsigned long src_pfn, dst_pfn = 0;
struct migrate_vma mig;
@@ -400,18 +469,6 @@ static int kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start,
mig.src = &src_pfn;
mig.dst = &dst_pfn;
- /*
- * We come here with mmap_sem write lock held just for
- * ksm_madvise(), otherwise we only need read mmap_sem.
- * Hence downgrade to read lock once ksm_madvise() is done.
- */
- ret = ksm_madvise(vma, vma->vm_start, vma->vm_end,
- MADV_UNMERGEABLE, &vma->vm_flags);
- downgrade_write(&kvm->mm->mmap_sem);
- *downgrade = true;
- if (ret)
- return ret;
-
ret = migrate_vma_setup(&mig);
if (ret)
return ret;
@@ -503,7 +560,6 @@ unsigned long kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa,
unsigned long flags,
unsigned long page_shift)
{
- bool downgrade = false;
unsigned long start, end;
struct vm_area_struct *vma;
int srcu_idx;
@@ -540,16 +596,12 @@ unsigned long kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa,
if (!vma || vma->vm_start > start || vma->vm_end < end)
goto out_unlock;
- if (!kvmppc_svm_page_in(vma, start, end, gpa, kvm, page_shift,
- &downgrade))
+ if (!kvmppc_svm_page_in(vma, start, end, gpa, kvm, page_shift))
ret = H_SUCCESS;
out_unlock:
mutex_unlock(&kvm->arch.uvmem_lock);
out:
- if (downgrade)
- up_read(&kvm->mm->mmap_sem);
- else
- up_write(&kvm->mm->mmap_sem);
+ up_write(&kvm->mm->mmap_sem);
srcu_read_unlock(&kvm->srcu, srcu_idx);
return ret;
}
--
1.8.3.1
^ permalink raw reply related
* [v3 2/5] KVM: PPC: Book3S HV: track the state of GFNs associated with secure VMs
From: Ram Pai @ 2020-07-11 9:13 UTC (permalink / raw)
To: kvm-ppc, linuxppc-dev
Cc: ldufour, linuxram, cclaudio, bharata, sathnaga, aneesh.kumar,
sukadev, bauerman, david
In-Reply-To: <1594458827-31866-1-git-send-email-linuxram@us.ibm.com>
During the life of SVM, its GFNs transition through normal, secure and
shared states. Since the kernel does not track GFNs that are shared, it
is not possible to disambiguate a shared GFN from a GFN whose PFN has
not yet been migrated to a secure-PFN. Also it is not possible to
disambiguate a secure-GFN from a GFN whose GFN has been pagedout from
the ultravisor.
The ability to identify the state of a GFN is needed to skip migration
of its PFN to secure-PFN during ESM transition.
The code is re-organized to track the states of a GFN as explained
below.
************************************************************************
1. States of a GFN
---------------
The GFN can be in one of the following states.
(a) Secure - The GFN is secure. The GFN is associated with
a Secure VM, the contents of the GFN is not accessible
to the Hypervisor. This GFN can be backed by a secure-PFN,
or can be backed by a normal-PFN with contents encrypted.
The former is true when the GFN is paged-in into the
ultravisor. The latter is true when the GFN is paged-out
of the ultravisor.
(b) Shared - The GFN is shared. The GFN is associated with a
a secure VM. The contents of the GFN is accessible to
Hypervisor. This GFN is backed by a normal-PFN and its
content is un-encrypted.
(c) Normal - The GFN is a normal. The GFN is associated with
a normal VM. The contents of the GFN is accesible to
the Hypervisor. Its content is never encrypted.
2. States of a VM.
---------------
(a) Normal VM: A VM whose contents are always accessible to
the hypervisor. All its GFNs are normal-GFNs.
(b) Secure VM: A VM whose contents are not accessible to the
hypervisor without the VM's consent. Its GFNs are
either Shared-GFN or Secure-GFNs.
(c) Transient VM: A Normal VM that is transitioning to secure VM.
The transition starts on successful return of
H_SVM_INIT_START, and ends on successful return
of H_SVM_INIT_DONE. This transient VM, can have GFNs
in any of the three states; i.e Secure-GFN, Shared-GFN,
and Normal-GFN. The VM never executes in this state
in supervisor-mode.
3. Memory slot State.
------------------
The state of a memory slot mirrors the state of the
VM the memory slot is associated with.
4. VM State transition.
--------------------
A VM always starts in Normal Mode.
H_SVM_INIT_START moves the VM into transient state. During this
time the Ultravisor may request some of its GFNs to be shared or
secured. So its GFNs can be in one of the three GFN states.
H_SVM_INIT_DONE moves the VM entirely from transient state to
secure-state. At this point any left-over normal-GFNs are
transitioned to Secure-GFN.
H_SVM_INIT_ABORT moves the transient VM back to normal VM.
All its GFNs are moved to Normal-GFNs.
UV_TERMINATE transitions the secure-VM back to normal-VM. All
the secure-GFN and shared-GFNs are tranistioned to normal-GFN
Note: The contents of the normal-GFN is undefined at this point.
5. GFN state implementation:
-------------------------
Secure GFN is associated with a secure-PFN; also called uvmem_pfn,
when the GFN is paged-in. Its pfn[] has KVMPPC_GFN_UVMEM_PFN flag
set, and contains the value of the secure-PFN.
It is associated with a normal-PFN; also called mem_pfn, when
the GFN is pagedout. Its pfn[] has KVMPPC_GFN_MEM_PFN flag set.
The value of the normal-PFN is not tracked.
Shared GFN is associated with a normal-PFN. Its pfn[] has
KVMPPC_UVMEM_SHARED_PFN flag set. The value of the normal-PFN
is not tracked.
Normal GFN is associated with normal-PFN. Its pfn[] has
no flag set. The value of the normal-PFN is not tracked.
6. Life cycle of a GFN
--------------------
--------------------------------------------------------------
| | Share | Unshare | SVM |H_SVM_INIT_DONE|
| |operation |operation | abort/ | |
| | | | terminate | |
-------------------------------------------------------------
| | | | | |
| Secure | Shared | Secure |Normal |Secure |
| | | | | |
| Shared | Shared | Secure |Normal |Shared |
| | | | | |
| Normal | Shared | Secure |Normal |Secure |
--------------------------------------------------------------
7. Life cycle of a VM
--------------------
--------------------------------------------------------------------
| | start | H_SVM_ |H_SVM_ |H_SVM_ |UV_SVM_ |
| | VM |INIT_START|INIT_DONE|INIT_ABORT |TERMINATE |
| | | | | | |
--------- ----------------------------------------------------------
| | | | | | |
| Normal | Normal | Transient|Error |Error |Normal |
| | | | | | |
| Secure | Error | Error |Error |Error |Normal |
| | | | | | |
|Transient| N/A | Error |Secure |Normal |Normal |
--------------------------------------------------------------------
************************************************************************
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Claudio Carvalho <cclaudio@linux.ibm.com>
Cc: kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
arch/powerpc/kvm/book3s_hv_uvmem.c | 187 +++++++++++++++++++++++++++++++++----
1 file changed, 168 insertions(+), 19 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
index bfc3841..6d6c256 100644
--- a/arch/powerpc/kvm/book3s_hv_uvmem.c
+++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
@@ -98,7 +98,127 @@
static unsigned long *kvmppc_uvmem_bitmap;
static DEFINE_SPINLOCK(kvmppc_uvmem_bitmap_lock);
-#define KVMPPC_UVMEM_PFN (1UL << 63)
+/*
+ * States of a GFN
+ * ---------------
+ * The GFN can be in one of the following states.
+ *
+ * (a) Secure - The GFN is secure. The GFN is associated with
+ * a Secure VM, the contents of the GFN is not accessible
+ * to the Hypervisor. This GFN can be backed by a secure-PFN,
+ * or can be backed by a normal-PFN with contents encrypted.
+ * The former is true when the GFN is paged-in into the
+ * ultravisor. The latter is true when the GFN is paged-out
+ * of the ultravisor.
+ *
+ * (b) Shared - The GFN is shared. The GFN is associated with a
+ * a secure VM. The contents of the GFN is accessible to
+ * Hypervisor. This GFN is backed by a normal-PFN and its
+ * content is un-encrypted.
+ *
+ * (c) Normal - The GFN is a normal. The GFN is associated with
+ * a normal VM. The contents of the GFN is accesible to
+ * the Hypervisor. Its content is never encrypted.
+ *
+ * States of a VM.
+ * ---------------
+ *
+ * Normal VM: A VM whose contents are always accessible to
+ * the hypervisor. All its GFNs are normal-GFNs.
+ *
+ * Secure VM: A VM whose contents are not accessible to the
+ * hypervisor without the VM's consent. Its GFNs are
+ * either Shared-GFN or Secure-GFNs.
+ *
+ * Transient VM: A Normal VM that is transitioning to secure VM.
+ * The transition starts on successful return of
+ * H_SVM_INIT_START, and ends on successful return
+ * of H_SVM_INIT_DONE. This transient VM, can have GFNs
+ * in any of the three states; i.e Secure-GFN, Shared-GFN,
+ * and Normal-GFN. The VM never executes in this state
+ * in supervisor-mode.
+ *
+ * Memory slot State.
+ * -----------------------------
+ * The state of a memory slot mirrors the state of the
+ * VM the memory slot is associated with.
+ *
+ * VM State transition.
+ * --------------------
+ *
+ * A VM always starts in Normal Mode.
+ *
+ * H_SVM_INIT_START moves the VM into transient state. During this
+ * time the Ultravisor may request some of its GFNs to be shared or
+ * secured. So its GFNs can be in one of the three GFN states.
+ *
+ * H_SVM_INIT_DONE moves the VM entirely from transient state to
+ * secure-state. At this point any left-over normal-GFNs are
+ * transitioned to Secure-GFN.
+ *
+ * H_SVM_INIT_ABORT moves the transient VM back to normal VM.
+ * All its GFNs are moved to Normal-GFNs.
+ *
+ * UV_TERMINATE transitions the secure-VM back to normal-VM. All
+ * the secure-GFN and shared-GFNs are tranistioned to normal-GFN
+ * Note: The contents of the normal-GFN is undefined at this point.
+ *
+ * GFN state implementation:
+ * -------------------------
+ *
+ * Secure GFN is associated with a secure-PFN; also called uvmem_pfn,
+ * when the GFN is paged-in. Its pfn[] has KVMPPC_GFN_UVMEM_PFN flag
+ * set, and contains the value of the secure-PFN.
+ * It is associated with a normal-PFN; also called mem_pfn, when
+ * the GFN is pagedout. Its pfn[] has KVMPPC_GFN_MEM_PFN flag set.
+ * The value of the normal-PFN is not tracked.
+ *
+ * Shared GFN is associated with a normal-PFN. Its pfn[] has
+ * KVMPPC_UVMEM_SHARED_PFN flag set. The value of the normal-PFN
+ * is not tracked.
+ *
+ * Normal GFN is associated with normal-PFN. Its pfn[] has
+ * no flag set. The value of the normal-PFN is not tracked.
+ *
+ * Life cycle of a GFN
+ * --------------------
+ *
+ * --------------------------------------------------------------
+ * | | Share | Unshare | SVM |H_SVM_INIT_DONE|
+ * | |operation |operation | abort/ | |
+ * | | | | terminate | |
+ * -------------------------------------------------------------
+ * | | | | | |
+ * | Secure | Shared | Secure |Normal |Secure |
+ * | | | | | |
+ * | Shared | Shared | Secure |Normal |Shared |
+ * | | | | | |
+ * | Normal | Shared | Secure |Normal |Secure |
+ * --------------------------------------------------------------
+ *
+ * Life cycle of a VM
+ * --------------------
+ *
+ * --------------------------------------------------------------------
+ * | | start | H_SVM_ |H_SVM_ |H_SVM_ |UV_SVM_ |
+ * | | VM |INIT_START|INIT_DONE|INIT_ABORT |TERMINATE |
+ * | | | | | | |
+ * --------- ----------------------------------------------------------
+ * | | | | | | |
+ * | Normal | Normal | Transient|Error |Error |Normal |
+ * | | | | | | |
+ * | Secure | Error | Error |Error |Error |Normal |
+ * | | | | | | |
+ * |Transient| N/A | Error |Secure |Normal |Normal |
+ * --------------------------------------------------------------------
+ */
+
+#define KVMPPC_GFN_UVMEM_PFN (1UL << 63)
+#define KVMPPC_GFN_MEM_PFN (1UL << 62)
+#define KVMPPC_GFN_SHARED (1UL << 61)
+#define KVMPPC_GFN_SECURE (KVMPPC_GFN_UVMEM_PFN | KVMPPC_GFN_MEM_PFN)
+#define KVMPPC_GFN_FLAG_MASK (KVMPPC_GFN_SECURE | KVMPPC_GFN_SHARED)
+#define KVMPPC_GFN_PFN_MASK (~KVMPPC_GFN_FLAG_MASK)
struct kvmppc_uvmem_slot {
struct list_head list;
@@ -106,11 +226,11 @@ struct kvmppc_uvmem_slot {
unsigned long base_pfn;
unsigned long *pfns;
};
-
struct kvmppc_uvmem_page_pvt {
struct kvm *kvm;
unsigned long gpa;
bool skip_page_out;
+ bool remove_gfn;
};
bool kvmppc_uvmem_available(void)
@@ -163,8 +283,8 @@ void kvmppc_uvmem_slot_free(struct kvm *kvm, const struct kvm_memory_slot *slot)
mutex_unlock(&kvm->arch.uvmem_lock);
}
-static void kvmppc_uvmem_pfn_insert(unsigned long gfn, unsigned long uvmem_pfn,
- struct kvm *kvm)
+static void kvmppc_mark_gfn(unsigned long gfn, struct kvm *kvm,
+ unsigned long flag, unsigned long uvmem_pfn)
{
struct kvmppc_uvmem_slot *p;
@@ -172,24 +292,41 @@ static void kvmppc_uvmem_pfn_insert(unsigned long gfn, unsigned long uvmem_pfn,
if (gfn >= p->base_pfn && gfn < p->base_pfn + p->nr_pfns) {
unsigned long index = gfn - p->base_pfn;
- p->pfns[index] = uvmem_pfn | KVMPPC_UVMEM_PFN;
+ if (flag == KVMPPC_GFN_UVMEM_PFN)
+ p->pfns[index] = uvmem_pfn | flag;
+ else
+ p->pfns[index] = flag;
return;
}
}
}
-static void kvmppc_uvmem_pfn_remove(unsigned long gfn, struct kvm *kvm)
+/* mark the GFN as secure-GFN associated with @uvmem pfn device-PFN. */
+static void kvmppc_gfn_secure_uvmem_pfn(unsigned long gfn,
+ unsigned long uvmem_pfn, struct kvm *kvm)
{
- struct kvmppc_uvmem_slot *p;
+ kvmppc_mark_gfn(gfn, kvm, KVMPPC_GFN_UVMEM_PFN, uvmem_pfn);
+}
- list_for_each_entry(p, &kvm->arch.uvmem_pfns, list) {
- if (gfn >= p->base_pfn && gfn < p->base_pfn + p->nr_pfns) {
- p->pfns[gfn - p->base_pfn] = 0;
- return;
- }
- }
+/* mark the GFN as secure-GFN associated with a memory-PFN. */
+static void kvmppc_gfn_secure_mem_pfn(unsigned long gfn, struct kvm *kvm)
+{
+ kvmppc_mark_gfn(gfn, kvm, KVMPPC_GFN_MEM_PFN, 0);
+}
+
+/* mark the GFN as a shared GFN. */
+static void kvmppc_gfn_shared(unsigned long gfn, struct kvm *kvm)
+{
+ kvmppc_mark_gfn(gfn, kvm, KVMPPC_GFN_SHARED, 0);
+}
+
+/* mark the GFN as a non-existent GFN. */
+static void kvmppc_gfn_remove(unsigned long gfn, struct kvm *kvm)
+{
+ kvmppc_mark_gfn(gfn, kvm, 0, 0);
}
+/* return true, if the GFN is a secure-GFN backed by a secure-PFN */
static bool kvmppc_gfn_is_uvmem_pfn(unsigned long gfn, struct kvm *kvm,
unsigned long *uvmem_pfn)
{
@@ -199,10 +336,10 @@ static bool kvmppc_gfn_is_uvmem_pfn(unsigned long gfn, struct kvm *kvm,
if (gfn >= p->base_pfn && gfn < p->base_pfn + p->nr_pfns) {
unsigned long index = gfn - p->base_pfn;
- if (p->pfns[index] & KVMPPC_UVMEM_PFN) {
+ if (p->pfns[index] & KVMPPC_GFN_UVMEM_PFN) {
if (uvmem_pfn)
*uvmem_pfn = p->pfns[index] &
- ~KVMPPC_UVMEM_PFN;
+ KVMPPC_GFN_PFN_MASK;
return true;
} else
return false;
@@ -353,6 +490,7 @@ void kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free,
mutex_lock(&kvm->arch.uvmem_lock);
if (!kvmppc_gfn_is_uvmem_pfn(gfn, kvm, &uvmem_pfn)) {
+ kvmppc_gfn_remove(gfn, kvm);
mutex_unlock(&kvm->arch.uvmem_lock);
continue;
}
@@ -360,6 +498,7 @@ void kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free,
uvmem_page = pfn_to_page(uvmem_pfn);
pvt = uvmem_page->zone_device_data;
pvt->skip_page_out = skip_page_out;
+ pvt->remove_gfn = true;
mutex_unlock(&kvm->arch.uvmem_lock);
pfn = gfn_to_pfn(kvm, gfn);
@@ -429,7 +568,7 @@ static struct page *kvmppc_uvmem_get_page(unsigned long gpa, struct kvm *kvm)
goto out_clear;
uvmem_pfn = bit + pfn_first;
- kvmppc_uvmem_pfn_insert(gpa >> PAGE_SHIFT, uvmem_pfn, kvm);
+ kvmppc_gfn_secure_uvmem_pfn(gpa >> PAGE_SHIFT, uvmem_pfn, kvm);
pvt->gpa = gpa;
pvt->kvm = kvm;
@@ -524,6 +663,7 @@ static unsigned long kvmppc_share_page(struct kvm *kvm, unsigned long gpa,
uvmem_page = pfn_to_page(uvmem_pfn);
pvt = uvmem_page->zone_device_data;
pvt->skip_page_out = true;
+ pvt->remove_gfn = false;
}
retry:
@@ -537,12 +677,16 @@ static unsigned long kvmppc_share_page(struct kvm *kvm, unsigned long gpa,
uvmem_page = pfn_to_page(uvmem_pfn);
pvt = uvmem_page->zone_device_data;
pvt->skip_page_out = true;
+ pvt->remove_gfn = false;
kvm_release_pfn_clean(pfn);
goto retry;
}
- if (!uv_page_in(kvm->arch.lpid, pfn << page_shift, gpa, 0, page_shift))
+ if (!uv_page_in(kvm->arch.lpid, pfn << page_shift, gpa, 0,
+ page_shift)) {
+ kvmppc_gfn_shared(gfn, kvm);
ret = H_SUCCESS;
+ }
kvm_release_pfn_clean(pfn);
mutex_unlock(&kvm->arch.uvmem_lock);
out:
@@ -598,6 +742,7 @@ unsigned long kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa,
if (!kvmppc_svm_page_in(vma, start, end, gpa, kvm, page_shift))
ret = H_SUCCESS;
+
out_unlock:
mutex_unlock(&kvm->arch.uvmem_lock);
out:
@@ -706,7 +851,8 @@ static vm_fault_t kvmppc_uvmem_migrate_to_ram(struct vm_fault *vmf)
/*
* Release the device PFN back to the pool
*
- * Gets called when secure page becomes a normal page during H_SVM_PAGE_OUT.
+ * Gets called when secure GFN tranistions from a secure-PFN
+ * to a normal PFN during H_SVM_PAGE_OUT.
* Gets called with kvm->arch.uvmem_lock held.
*/
static void kvmppc_uvmem_page_free(struct page *page)
@@ -721,7 +867,10 @@ static void kvmppc_uvmem_page_free(struct page *page)
pvt = page->zone_device_data;
page->zone_device_data = NULL;
- kvmppc_uvmem_pfn_remove(pvt->gpa >> PAGE_SHIFT, pvt->kvm);
+ if (pvt->remove_gfn)
+ kvmppc_gfn_remove(pvt->gpa >> PAGE_SHIFT, pvt->kvm);
+ else
+ kvmppc_gfn_secure_mem_pfn(pvt->gpa >> PAGE_SHIFT, pvt->kvm);
kfree(pvt);
}
--
1.8.3.1
^ permalink raw reply related
* [PATCH v2] powerpc/pseries: detect secure and trusted boot state of the system.
From: Nayna Jain @ 2020-07-11 2:25 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nayna Jain, linux-kernel, Mimi Zohar
The device-tree property to check secure and trusted boot state is
different for guests(pseries) compared to baremetal(powernv).
This patch updates the existing is_ppc_secureboot_enabled() and
is_ppc_trustedboot_enabled() function to add support for pseries.
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
---
v2:
* included Michael Ellerman's feedback.
* added Daniel Axtens's Reviewed-by.
arch/powerpc/kernel/secure_boot.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/secure_boot.c b/arch/powerpc/kernel/secure_boot.c
index 4b982324d368..efb325cbd42f 100644
--- a/arch/powerpc/kernel/secure_boot.c
+++ b/arch/powerpc/kernel/secure_boot.c
@@ -6,6 +6,7 @@
#include <linux/types.h>
#include <linux/of.h>
#include <asm/secure_boot.h>
+#include <asm/machdep.h>
static struct device_node *get_ppc_fw_sb_node(void)
{
@@ -23,12 +24,21 @@ bool is_ppc_secureboot_enabled(void)
{
struct device_node *node;
bool enabled = false;
+ u32 secureboot;
node = get_ppc_fw_sb_node();
enabled = of_property_read_bool(node, "os-secureboot-enforcing");
-
of_node_put(node);
+ if (enabled)
+ goto out;
+
+ if (!of_property_read_u32(of_root, "ibm,secure-boot", &secureboot)) {
+ if (secureboot)
+ enabled = (secureboot > 1) ? true : false;
+ }
+
+out:
pr_info("Secure boot mode %s\n", enabled ? "enabled" : "disabled");
return enabled;
@@ -38,12 +48,21 @@ bool is_ppc_trustedboot_enabled(void)
{
struct device_node *node;
bool enabled = false;
+ u32 trustedboot;
node = get_ppc_fw_sb_node();
enabled = of_property_read_bool(node, "trusted-enabled");
-
of_node_put(node);
+ if (enabled)
+ goto out;
+
+ if (!of_property_read_u32(of_root, "ibm,trusted-boot", &trustedboot)) {
+ if (trustedboot)
+ enabled = (trustedboot > 0) ? true : false;
+ }
+
+out:
pr_info("Trusted boot mode %s\n", enabled ? "enabled" : "disabled");
return enabled;
--
2.26.2
^ permalink raw reply related
* [PATCH V2 2/2] selftests/powerpc: Use proper error code to check fault address
From: Haren Myneni @ 2020-07-10 23:49 UTC (permalink / raw)
To: mpe; +Cc: tulioqm, linuxppc-dev, abali, rzinsly
In-Reply-To: <019fd53e7538c6f8f332d175df74b1815ef5aa8c.camel@linux.ibm.com>
ERR_NX_TRANSLATION(CSB.CC=5) is for internal to VAS for fault handling
and should not used by OS. ERR_NX_AT_FAULT(CSB.CC=250) is the proper
error code should be reported by OS when NX encounters address
translation failure.
This patch uses CC=250 to determine the fault address when the request
is not successful.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
tools/testing/selftests/powerpc/nx-gzip/gunz_test.c | 4 ++--
tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/powerpc/nx-gzip/gunz_test.c b/tools/testing/selftests/powerpc/nx-gzip/gunz_test.c
index 6ee0fde..7c23d3d 100644
--- a/tools/testing/selftests/powerpc/nx-gzip/gunz_test.c
+++ b/tools/testing/selftests/powerpc/nx-gzip/gunz_test.c
@@ -698,13 +698,13 @@ int decompress_file(int argc, char **argv, void *devhandle)
switch (cc) {
- case ERR_NX_TRANSLATION:
+ case ERR_NX_AT_FAULT:
/* We touched the pages ahead of time. In the most common case
* we shouldn't be here. But may be some pages were paged out.
* Kernel should have placed the faulting address to fsaddr.
*/
- NXPRT(fprintf(stderr, "ERR_NX_TRANSLATION %p\n",
+ NXPRT(fprintf(stderr, "ERR_NX_AT_FAULT %p\n",
(void *)cmdp->crb.csb.fsaddr));
if (pgfault_retries == NX_MAX_FAULTS) {
diff --git a/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c b/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c
index 7496a83..02dffb6 100644
--- a/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c
+++ b/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c
@@ -306,13 +306,13 @@ int compress_file(int argc, char **argv, void *handle)
lzcounts, cmdp, handle);
if (cc != ERR_NX_OK && cc != ERR_NX_TPBC_GT_SPBC &&
- cc != ERR_NX_TRANSLATION) {
+ cc != ERR_NX_AT_FAULT) {
fprintf(stderr, "nx error: cc= %d\n", cc);
exit(-1);
}
/* Page faults are handled by the user code */
- if (cc == ERR_NX_TRANSLATION) {
+ if (cc == ERR_NX_AT_FAULT) {
NXPRT(fprintf(stderr, "page fault: cc= %d, ", cc));
NXPRT(fprintf(stderr, "try= %d, fsa= %08llx\n",
fault_tries,
--
1.8.3.1
^ permalink raw reply related
* [PATCH V2 1/2] powerpc/vas: Report proper error code for address translation failure
From: Haren Myneni @ 2020-07-10 23:47 UTC (permalink / raw)
To: mpe; +Cc: tulioqm, abali, linuxppc-dev, rzinsly
P9 DD2 NX workbook (Table 4-36) says DMA controller uses CC=5
internally for translation fault handling. NX reserves CC=250 for
OS to notify user space when NX encounters address translation
failure on the request buffer. Not an issue in earlier releases
as NX does not get faults on kernel addresses.
This patch defines CSB_CC_FAULT_ADDRESS(250) and updates CSB.CC with
this proper error code for user space.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Changes in V2:
- Use CSB_CC_FAULT_ADDRESS instead of CSB_CC_ADDRESS_TRANSLATION
to distinguish from other error codes.
- Add NX workbook reference in the comment.
---
Documentation/powerpc/vas-api.rst | 2 +-
arch/powerpc/include/asm/icswx.h | 4 ++++
arch/powerpc/platforms/powernv/vas-fault.c | 2 +-
3 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/Documentation/powerpc/vas-api.rst b/Documentation/powerpc/vas-api.rst
index 1217c2f..788dc83 100644
--- a/Documentation/powerpc/vas-api.rst
+++ b/Documentation/powerpc/vas-api.rst
@@ -213,7 +213,7 @@ request buffers are not in memory. The operating system handles the fault by
updating CSB with the following data:
csb.flags = CSB_V;
- csb.cc = CSB_CC_TRANSLATION;
+ csb.cc = CSB_CC_FAULT_ADDRESS;
csb.ce = CSB_CE_TERMINATION;
csb.address = fault_address;
diff --git a/arch/powerpc/include/asm/icswx.h b/arch/powerpc/include/asm/icswx.h
index 965b1f3..9bc7c58 100644
--- a/arch/powerpc/include/asm/icswx.h
+++ b/arch/powerpc/include/asm/icswx.h
@@ -77,6 +77,10 @@ struct coprocessor_completion_block {
#define CSB_CC_CHAIN (37)
#define CSB_CC_SEQUENCE (38)
#define CSB_CC_HW (39)
+/*
+ * P9 DD NX Workbook 3.2 (Table 4-36): Address translation fault
+ */
+#define CSB_CC_FAULT_ADDRESS (250)
#define CSB_SIZE (0x10)
#define CSB_ALIGN CSB_SIZE
diff --git a/arch/powerpc/platforms/powernv/vas-fault.c b/arch/powerpc/platforms/powernv/vas-fault.c
index 266a6ca..3d21fce 100644
--- a/arch/powerpc/platforms/powernv/vas-fault.c
+++ b/arch/powerpc/platforms/powernv/vas-fault.c
@@ -79,7 +79,7 @@ static void update_csb(struct vas_window *window,
csb_addr = (void __user *)be64_to_cpu(crb->csb_addr);
memset(&csb, 0, sizeof(csb));
- csb.cc = CSB_CC_TRANSLATION;
+ csb.cc = CSB_CC_FAULT_ADDRESS;
csb.ce = CSB_CE_TERMINATION;
csb.cs = 0;
csb.count = 0;
--
1.8.3.1
^ permalink raw reply related
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