treewide: update LLVM Bugzilla links

LLVM moved their issue tracker from their own Bugzilla instance to GitHub
issues. While all of the links are still valid, they may not necessarily
show the most

treewide: update LLVM Bugzilla links

LLVM moved their issue tracker from their own Bugzilla instance to GitHub
issues. While all of the links are still valid, they may not necessarily
show the most up to date information around the issues, as all updates
will occur on GitHub, not Bugzilla.

Another complication is that the Bugzilla issue number is not always the
same as the GitHub issue number. Thankfully, LLVM maintains this mapping
through two shortlinks:

https://llvm.org/bz<num> -> https://bugs.llvm.org/show_bug.cgi?id=<num>
https://llvm.org/pr<num> -> https://github.com/llvm/llvm-project/issues/<mapped_num>

Switch all "https://bugs.llvm.org/show_bug.cgi?id=<num>" links to the
"https://llvm.org/pr<num>" shortlink so that the links show the most up to
date information. Each migrated issue links back to the Bugzilla entry,
so there should be no loss of fidelity of information here.

Link: https://lkml.kernel.org/r/20240109-update-llvm-links-v1-3-eb09b59db071@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Fangrui Song <maskray@google.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Mykola Lysenko <mykolal@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

KVM: PPC: Book3S HV nestedv2: Invalidate RPT before deleting a guest

An L0 must invalidate the L2's RPT during H_GUEST_DELETE if this has not
already been done. This is a slow operation that means H

KVM: PPC: Book3S HV nestedv2: Invalidate RPT before deleting a guest

An L0 must invalidate the L2's RPT during H_GUEST_DELETE if this has not
already been done. This is a slow operation that means H_GUEST_DELETE
must return H_BUSY multiple times before completing. Invalidating the
tables before deleting the guest so there is less work for the L0 to do.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231201132618.555031-2-vaibhav@linux.ibm.com

show more ...

KVM: PPC: Add support for nestedv2 guests

A series of hcalls have been added to the PAPR which allow a regular
guest partition to create and manage guest partitions of its own. KVM
already had an in

KVM: PPC: Add support for nestedv2 guests

A series of hcalls have been added to the PAPR which allow a regular
guest partition to create and manage guest partitions of its own. KVM
already had an interface that allowed this on powernv platforms. This
existing interface will now be called "nestedv1". The newly added PAPR
interface will be called "nestedv2". PHYP will support the nestedv2
interface. At this time the host side of the nestedv2 interface has not
been implemented on powernv but there is no technical reason why it
could not be added.

The nestedv1 interface is still supported.

Add support to KVM to utilize these hcalls to enable running nested
guests as a pseries guest on PHYP.

Overview of the new hcall usage:

- L1 and L0 negotiate capabilities with
H_GUEST_{G,S}ET_CAPABILITIES()

- L1 requests the L0 create a L2 with
H_GUEST_CREATE() and receives a handle to use in future hcalls

- L1 requests the L0 create a L2 vCPU with
H_GUEST_CREATE_VCPU()

- L1 sets up the L2 using H_GUEST_SET and the
H_GUEST_VCPU_RUN input buffer

- L1 requests the L0 runs the L2 vCPU using H_GUEST_VCPU_RUN()

- L2 returns to L1 with an exit reason and L1 reads the
H_GUEST_VCPU_RUN output buffer populated by the L0

- L1 handles the exit using H_GET_STATE if necessary

- L1 reruns L2 vCPU with H_GUEST_VCPU_RUN

- L1 frees the L2 in the L0 with H_GUEST_DELETE()

Support for the new API is determined by trying
H_GUEST_GET_CAPABILITIES. On a successful return, use the nestedv2
interface.

Use the vcpu register state setters for tracking modified guest state
elements and copy the thread wide values into the H_GUEST_VCPU_RUN input
buffer immediately before running a L2. The guest wide
elements can not be added to the input buffer so send them with a
separate H_GUEST_SET call if necessary.

Make the vcpu register getter load the corresponding value from the real
host with H_GUEST_GET. To avoid unnecessarily calling H_GUEST_GET, track
which values have already been loaded between H_GUEST_VCPU_RUN calls. If
an element is present in the H_GUEST_VCPU_RUN output buffer it also does
not need to be loaded again.

Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Gautam Menghani <gautam@linux.ibm.com>
Signed-off-by: Kautuk Consul <kconsul@linux.vnet.ibm.com>
Signed-off-by: Amit Machhiwal <amachhiw@linux.vnet.ibm.com>
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230914030600.16993-11-jniethe5@gmail.com

show more ...

KVM: PPC: Book3s HV: Hold LPIDs in an unsigned long

The LPID register is 32 bits long. The host keeps the lpids for each
guest in an unsigned word struct kvm_arch. Currently, LPIDs are already
limit

KVM: PPC: Book3s HV: Hold LPIDs in an unsigned long

The LPID register is 32 bits long. The host keeps the lpids for each
guest in an unsigned word struct kvm_arch. Currently, LPIDs are already
limited by mmu_lpid_bits and KVM_MAX_NESTED_GUESTS_SHIFT.

The nestedv2 API returns a 64 bit "Guest ID" to be used be the L1 host
for each L2 guest. This value is used as an lpid, e.g. it is the
parameter used by H_RPT_INVALIDATE. To minimize needless special casing
it makes sense to keep this "Guest ID" in struct kvm_arch::lpid.

This means that struct kvm_arch::lpid is too small so prepare for this
and make it an unsigned long. This is not a problem for the KVM-HV and
nestedv1 cases as their lpid values are already limited to valid ranges
so in those contexts the lpid can be used as an unsigned word safely as
needed.

In the PAPR, the H_RPT_INVALIDATE pid/lpid parameter is already
specified as an unsigned long so change pseries_rpt_invalidate() to
match that. Update the callers of pseries_rpt_invalidate() to also take
an unsigned long if they take an lpid value.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230914030600.16993-10-jniethe5@gmail.com

show more ...

KVM: PPC: Book3S HV: Set SRR1[PREFIX] bit on injected interrupts

Pass the hypervisor (H)SRR1[PREFIX] indication through to synchronous
interrupts injected into the guest.

Signed-off-by: Nicholas Pi

KVM: PPC: Book3S HV: Set SRR1[PREFIX] bit on injected interrupts

Pass the hypervisor (H)SRR1[PREFIX] indication through to synchronous
interrupts injected into the guest.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230330103224.3589928-3-npiggin@gmail.com

show more ...

KVM: PPC: Permit SRR1 flags in more injected interrupt types

The prefix architecture in ISA v3.1 introduces a prefixed bit in SRR1
for many types of synchronous interrupts which is set when the inte

KVM: PPC: Permit SRR1 flags in more injected interrupt types

The prefix architecture in ISA v3.1 introduces a prefixed bit in SRR1
for many types of synchronous interrupts which is set when the interrupt
is caused by a prefixed instruction.

This requires KVM to be able to set this bit when injecting interrupts
into a guest. Plumb through the SRR1 "flags" argument to the core_queue
APIs where it's missing for this. For now they are set to 0, which is
no change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fixup kvmppc_core_queue_alignment() in booke.c]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230330103224.3589928-2-npiggin@gmail.com

show more ...

KVM: Rename mmu_notifier_* to mmu_invalidate_*

The motivation of this renaming is to make these variables and related
helper functions less mmu_notifier bound and can also be used for non
mmu_notifi

KVM: Rename mmu_notifier_* to mmu_invalidate_*

The motivation of this renaming is to make these variables and related
helper functions less mmu_notifier bound and can also be used for non
mmu_notifier based page invalidation. mmu_invalidate_* was chosen to
better describe the purpose of 'invalidating' a page that those
variables are used for.

- mmu_notifier_seq/range_start/range_end are renamed to
mmu_invalidate_seq/range_start/range_end.

- mmu_notifier_retry{_hva} helper functions are renamed to
mmu_invalidate_retry{_hva}.

- mmu_notifier_count is renamed to mmu_invalidate_in_progress to
avoid confusion with mn_active_invalidate_count.

- While here, also update kvm_inc/dec_notifier_count() to
kvm_mmu_invalidate_begin/end() to match the change for
mmu_notifier_count.

No functional change intended.

Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Message-Id: <20220816125322.1110439-3-chao.p.peng@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

powerpc: Include asm/firmware.h in all users of firmware_has_feature()

Trying to remove asm/ppc_asm.h from all places that don't need it
leads to several failures linked to firmware_has_feature().

powerpc: Include asm/firmware.h in all users of firmware_has_feature()

Trying to remove asm/ppc_asm.h from all places that don't need it
leads to several failures linked to firmware_has_feature().

To fix it, include asm/firmware.h in all files using
firmware_has_feature()

All users found with:

git grep -L "firmware\.h" ` git grep -l "firmware_has_feature("`

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/11956ec181a034b51a881ac9c059eea72c679a73.1651828453.git.christophe.leroy@csgroup.eu

show more ...

KVM: PPC: Book3S HV Nested: L2 LPCR should inherit L1 LPES setting

The L1 should not be able to adjust LPES mode for the L2. Setting LPES
if the L0 needs it clear would cause external interrupts to

KVM: PPC: Book3S HV Nested: L2 LPCR should inherit L1 LPES setting

The L1 should not be able to adjust LPES mode for the L2. Setting LPES
if the L0 needs it clear would cause external interrupts to be sent to
L2 and missed by the L0.

Clearing LPES when it may be set, as typically happens with XIVE enabled
could cause a performance issue despite having no native XIVE support in
the guest, because it will cause mediated interrupts for the L2 to be
taken in HV mode, which then have to be injected.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220303053315.1056880-7-npiggin@gmail.com

show more ...

KVM: PPC: Book3S Nested: Use explicit 4096 LPID maximum

Rather than tie this to KVMPPC_NR_LPIDS which is becoming more dynamic,
fix it to 4096 (12-bits) explicitly for now.

kvmhv_get_nested() does

KVM: PPC: Book3S Nested: Use explicit 4096 LPID maximum

Rather than tie this to KVMPPC_NR_LPIDS which is becoming more dynamic,
fix it to 4096 (12-bits) explicitly for now.

kvmhv_get_nested() does not have to check against KVM_MAX_NESTED_GUESTS
because the L1 partition table registration hcall already did that, and
it checks against the partition table size.

This patch also puts all the partition table size calculations into the
same form, using 12 for the architected size field shift and 4 for the
shift corresponding to the partition table entry size.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-of-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220123120043.3586018-6-npiggin@gmail.com

show more ...

KVM: PPC: Book3S HV Nested: Change nested guest lookup to use idr

This removes the fixed sized kvm->arch.nested_guests array.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano

KVM: PPC: Book3S HV Nested: Change nested guest lookup to use idr

This removes the fixed sized kvm->arch.nested_guests array.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220123120043.3586018-5-npiggin@gmail.com

show more ...

KVM: Add helpers to wrap vcpu->srcu_idx and yell if it's abused

Add wrappers to acquire/release KVM's SRCU lock when stashing the index
in vcpu->src_idx, along with rudimentary detection of illegal

KVM: Add helpers to wrap vcpu->srcu_idx and yell if it's abused

Add wrappers to acquire/release KVM's SRCU lock when stashing the index
in vcpu->src_idx, along with rudimentary detection of illegal usage,
e.g. re-acquiring SRCU and thus overwriting vcpu->src_idx. Because the
SRCU index is (currently) either 0 or 1, illegal nesting bugs can go
unnoticed for quite some time and only cause problems when the nested
lock happens to get a different index.

Wrap the WARNs in PROVE_RCU=y, and make them ONCE, otherwise KVM will
likely yell so loudly that it will bring the kernel to its knees.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Tested-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20220415004343.2203171-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

KVM: PPC: Book3S HV Nested: Fix nested HFSCR being clobbered with multiple vCPUs

The L0 is storing HFSCR requested by the L1 for the L2 in struct
kvm_nested_guest when the L1 requests a vCPU enter L

KVM: PPC: Book3S HV Nested: Fix nested HFSCR being clobbered with multiple vCPUs

The L0 is storing HFSCR requested by the L1 for the L2 in struct
kvm_nested_guest when the L1 requests a vCPU enter L2. kvm_nested_guest
is not a per-vCPU structure. Hilarity ensues.

Fix it by moving the nested hfscr into the vCPU structure together with
the other per-vCPU nested fields.

Fixes: 8b210a880b35 ("KVM: PPC: Book3S HV Nested: Make nested HFSCR state accessible")
Cc: stable@vger.kernel.org # v5.15+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220122105530.3477250-1-npiggin@gmail.com

show more ...

KVM: Keep memslots in tree-based structures instead of array-based ones

The current memslot code uses a (reverse gfn-ordered) memslot array for
keeping track of them.

Because the memslot array that

KVM: Keep memslots in tree-based structures instead of array-based ones

The current memslot code uses a (reverse gfn-ordered) memslot array for
keeping track of them.

Because the memslot array that is currently in use cannot be modified
every memslot management operation (create, delete, move, change flags)
has to make a copy of the whole array so it has a scratch copy to work on.

Strictly speaking, however, it is only necessary to make copy of the
memslot that is being modified, copying all the memslots currently present
is just a limitation of the array-based memslot implementation.

Two memslot sets, however, are still needed so the VM continues to run
on the currently active set while the requested operation is being
performed on the second, currently inactive one.

In order to have two memslot sets, but only one copy of actual memslots
it is necessary to split out the memslot data from the memslot sets.

The memslots themselves should be also kept independent of each other
so they can be individually added or deleted.

These two memslot sets should normally point to the same set of
memslots. They can, however, be desynchronized when performing a
memslot management operation by replacing the memslot to be modified
by its copy. After the operation is complete, both memslot sets once
again point to the same, common set of memslot data.

This commit implements the aforementioned idea.

For tracking of gfns an ordinary rbtree is used since memslots cannot
overlap in the guest address space and so this data structure is
sufficient for ensuring that lookups are done quickly.

The "last used slot" mini-caches (both per-slot set one and per-vCPU one),
that keep track of the last found-by-gfn memslot, are still present in the
new code.

Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>

show more ...

KVM: PPC: Book3S: Suppress failed alloc warning in H_COPY_TOFROM_GUEST

H_COPY_TOFROM_GUEST is an hcall for an upper level VM to access its nested
VMs memory. The userspace can trigger WARN_ON_ONCE(!

KVM: PPC: Book3S: Suppress failed alloc warning in H_COPY_TOFROM_GUEST

H_COPY_TOFROM_GUEST is an hcall for an upper level VM to access its nested
VMs memory. The userspace can trigger WARN_ON_ONCE(!(gfp & __GFP_NOWARN))
in __alloc_pages() by constructing a tiny VM which only does
H_COPY_TOFROM_GUEST with a too big GPR9 (number of bytes to copy).

This silences the warning by adding __GFP_NOWARN.

Spotted by syzkaller.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210901084550.1658699-1-aik@ozlabs.ru

show more ...

KVM: PPC: Book3S HV Nested: Avoid extra mftb() in nested entry

mftb() is expensive and one can be avoided on nested guest dispatch.

If the time checking code distinguishes between the L0 timer and

KVM: PPC: Book3S HV Nested: Avoid extra mftb() in nested entry

mftb() is expensive and one can be avoided on nested guest dispatch.

If the time checking code distinguishes between the L0 timer and the
nested HV timer, then both can be tested in the same place with the
same mftb() value.

This also nicely illustrates the relationship between the L0 and nested
HV timers.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-45-npiggin@gmail.com

show more ...

KVM: PPC: Book3S HV: Change dec_expires to be relative to guest timebase

Change dec_expires to be relative to the guest timebase, and allow
it to be moved into low level P9 guest entry functions, to

KVM: PPC: Book3S HV: Change dec_expires to be relative to guest timebase

Change dec_expires to be relative to the guest timebase, and allow
it to be moved into low level P9 guest entry functions, to improve
SPR access scheduling.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-23-npiggin@gmail.com

show more ...

KVM: PPC: Book3S HV Nested: save_hv_return_state does not require trap argument

vcpu is already anargument so vcpu->arch.trap can be used directly.

Signed-off-by: Fabiano Rosas <farosas@linux.ibm.c

KVM: PPC: Book3S HV Nested: save_hv_return_state does not require trap argument

vcpu is already anargument so vcpu->arch.trap can be used directly.

Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210811160134.904987-9-npiggin@gmail.com

show more ...

KVM: PPC: Book3S HV Nested: Make nested HFSCR state accessible

When the L0 runs a nested L2, there are several permutations of HFSCR
that can be relevant. The HFSCR that the L1 vcpu L1 requested, th

KVM: PPC: Book3S HV Nested: Make nested HFSCR state accessible

When the L0 runs a nested L2, there are several permutations of HFSCR
that can be relevant. The HFSCR that the L1 vcpu L1 requested, the
HFSCR that the L1 vcpu may use, and the HFSCR that is actually being
used to run the L2.

The L1 requested HFSCR is not accessible outside the nested hcall
handler, so copy that into a new kvm_nested_guest.hfscr field.

The permitted HFSCR is taken from the HFSCR that the L1 runs with,
which is also not accessible while the hcall is being made. Move
this into a new kvm_vcpu_arch.hfscr_permitted field.

These will be used by the next patch to improve facility handling
for nested guests, and later by facility demand faulting patches.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210811160134.904987-7-npiggin@gmail.com

show more ...

KVM: PPC: Book3S HV Nested: Sanitise vcpu registers

As one of the arguments of the H_ENTER_NESTED hypercall, the nested
hypervisor (L1) prepares a structure containing the values of various
hypervis

KVM: PPC: Book3S HV Nested: Sanitise vcpu registers

As one of the arguments of the H_ENTER_NESTED hypercall, the nested
hypervisor (L1) prepares a structure containing the values of various
hypervisor-privileged registers with which it wants the nested guest
(L2) to run. Since the nested HV runs in supervisor mode it needs the
host to write to these registers.

To stop a nested HV manipulating this mechanism and using a nested
guest as a proxy to access a facility that has been made unavailable
to it, we have a routine that sanitises the values of the HV registers
before copying them into the nested guest's vcpu struct.

However, when coming out of the guest the values are copied as they
were back into L1 memory, which means that any sanitisation we did
during guest entry will be exposed to L1 after H_ENTER_NESTED returns.

This patch alters this sanitisation to have effect on the vcpu->arch
registers directly before entering and after exiting the guest,
leaving the structure that is copied back into L1 unchanged (except
when we really want L1 to access the value, e.g the Cause bits of
HFSCR).

Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Link: https://lore.kernel.org/r/20210811160134.904987-6-npiggin@gmail.com

show more ...

KVM: PPC: Book3S HV Nested: Sanitise H_ENTER_NESTED TM state

The H_ENTER_NESTED hypercall is handled by the L0, and it is a request
by the L1 to switch the context of the vCPU over to that of its L2

KVM: PPC: Book3S HV Nested: Sanitise H_ENTER_NESTED TM state

The H_ENTER_NESTED hypercall is handled by the L0, and it is a request
by the L1 to switch the context of the vCPU over to that of its L2
guest, and return with an interrupt indication. The L1 is responsible
for switching some registers to guest context, and the L0 switches
others (including all the hypervisor privileged state).

If the L2 MSR has TM active, then the L1 is responsible for
recheckpointing the L2 TM state. Then the L1 exits to L0 via the
H_ENTER_NESTED hcall, and the L0 saves the TM state as part of the exit,
and then it recheckpoints the TM state as part of the nested entry and
finally HRFIDs into the L2 with TM active MSR. Not efficient, but about
the simplest approach for something that's horrendously complicated.

Problems arise if the L1 exits to the L0 with a TM state which does not
match the L2 TM state being requested. For example if the L1 is
transactional but the L2 MSR is non-transactional, or vice versa. The
L0's HRFID can take a TM Bad Thing interrupt and crash.

Fix this by disallowing H_ENTER_NESTED in TM[T] state entirely, and then
ensuring that if the L1 is suspended then the L2 must have TM active,
and if the L1 is not suspended then the L2 must not have TM active.

Fixes: 360cae313702 ("KVM: PPC: Book3S HV: Nested guest entry via hypercall")
Cc: stable@vger.kernel.org # v4.20+
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

show more ...

KVM: PPC: Book3S HV: Workaround high stack usage with clang

LLVM does not emit optimal byteswap assembly, which results in high
stack usage in kvmhv_enter_nested_guest() due to the inlining of
bytes

KVM: PPC: Book3S HV: Workaround high stack usage with clang

LLVM does not emit optimal byteswap assembly, which results in high
stack usage in kvmhv_enter_nested_guest() due to the inlining of
byteswap_pt_regs(). With LLVM 12.0.0:

arch/powerpc/kvm/book3s_hv_nested.c:289:6: error: stack frame size of
2512 bytes in function 'kvmhv_enter_nested_guest' [-Werror,-Wframe-larger-than=]
long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
^
1 error generated.

While this gets fixed in LLVM, mark byteswap_pt_regs() as
noinline_for_stack so that it does not get inlined and break the build
due to -Werror by default in arch/powerpc/. Not inlining saves
approximately 800 bytes with LLVM 12.0.0:

arch/powerpc/kvm/book3s_hv_nested.c:290:6: warning: stack frame size of
1728 bytes in function 'kvmhv_enter_nested_guest' [-Wframe-larger-than=]
long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
^
1 warning generated.

Cc: stable@vger.kernel.org # v4.20+
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/ClangBuiltLinux/linux/issues/1292
Link: https://bugs.llvm.org/show_bug.cgi?id=49610
Link: https://lore.kernel.org/r/202104031853.vDT0Qjqj-lkp@intel.com/
Link: https://gist.github.com/ba710e3703bf45043a31e2806c843ffd
Link: https://lore.kernel.org/r/20210621182440.990242-1-nathan@kernel.org

show more ...

KVM: PPC: Book3S HV: Use H_RPT_INVALIDATE in nested KVM

In the nested KVM case, replace H_TLB_INVALIDATE by the new hcall
H_RPT_INVALIDATE if available. The availability of this hcall
is determined

KVM: PPC: Book3S HV: Use H_RPT_INVALIDATE in nested KVM

In the nested KVM case, replace H_TLB_INVALIDATE by the new hcall
H_RPT_INVALIDATE if available. The availability of this hcall
is determined from "hcall-rpt-invalidate" string in ibm,hypertas-functions
DT property.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-7-bharata@linux.ibm.com

show more ...

KVM: PPC: Book3S HV: Nested support in H_RPT_INVALIDATE

Enable support for process-scoped invalidations from nested
guests and partition-scoped invalidations for nested guests.

Process-scoped inval

KVM: PPC: Book3S HV: Nested support in H_RPT_INVALIDATE

Enable support for process-scoped invalidations from nested
guests and partition-scoped invalidations for nested guests.

Process-scoped invalidations for any level of nested guests
are handled by implementing H_RPT_INVALIDATE handler in the
nested guest exit path in L0.

Partition-scoped invalidation requests are forwarded to the
right nested guest, handled there and passed down to L0
for eventual handling.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
[aneesh: Nested guest partition-scoped invalidation changes]
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Squash in fixup patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-5-bharata@linux.ibm.com

show more ...

KVM: PPC: Book3S HV: Ensure MSR[HV] is always clear in guest MSR

Rather than clear the HV bit from the MSR at guest entry, make it clear
that the hypervisor does not allow the guest to set the bit.

KVM: PPC: Book3S HV: Ensure MSR[HV] is always clear in guest MSR

Rather than clear the HV bit from the MSR at guest entry, make it clear
that the hypervisor does not allow the guest to set the bit.

The HV clear is kept in guest entry for now, but a future patch will
warn if it is set.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210412014845.1517916-13-npiggin@gmail.com

show more ...