Commit Graph

34 Commits

Author SHA1 Message Date
Cédric Le Goater
36387ca51c target/ppc: Fix radix logging
ppc_radix64_partition_scoped_xlate() logs the host page protection
bits variable but it is uninitialized. The value is set later on in
ppc_radix64_check_prot(). Remove the output.

Fixes: Coverity CID 1468942
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20220203142145.1301749-1-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-02-09 09:08:55 +01:00
Cédric Le Goater
9b4eaee4d4 target/ppc: Check effective address validity
For Radix translation, the EA range is 64-bits. when EA(2:11) are
nonzero, a segment interrupt should occur.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Message-Id: <20211231073122.3183583-1-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-01-04 07:55:34 +01:00
Cédric Le Goater
932de56970 target/ppc: Improve logging in Radix MMU
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211222071002.1568894-1-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-01-04 07:55:34 +01:00
Bruno Larsen (billionai)
3f9f76d5bb target/ppc: fix address translation bug for radix mmus
This commit attempts to fix a technical hiccup first mentioned by Richard
Henderson in
https://lists.nongnu.org/archive/html/qemu-devel/2021-05/msg06247.html

To sumarize the hiccup here, when radix-style mmus are translating an
address, they might need to call a second level of translation, with
hypervisor privileges. However, the way it was being done up until
this point meant that the second level translation had the same
privileges as the first level. It could lead to a bug in address
translation when running KVM inside a TCG guest, but this bug was never
experienced by users, so this isn't as much a bug fix as it is a
correctness cleanup.

This patch attempts that cleanup by making radix64_*_xlate functions
receive the mmu_idx, and passing one with the correct permission for the
second level translation.

The mmuidx macros added by this patch are only correct for non-bookE
mmus, because BookE style set the IS and DS bits inverted and there
might be other subtle differences. However, there doesn't seem to be
BookE cpus that have radix-style mmus, so we left a comment there to
document the issue, in case a machine does have that and was missed.

As part of this cleanup, we now need to send the correct mmmu_idx
when calling get_phys_page_debug, otherwise we might not be able to see the
memory that the CPU could

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20210628133610.1143-2-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-07-09 10:38:19 +10:00
Richard Henderson
51806b5458 target/ppc: Introduce ppc_xlate
Create one common dispatch for all of the ppc_*_xlate functions.
Use ppc64_v3_radix to directly dispatch between ppc_radix64_xlate
and ppc_hash64_xlate.

Remove the separate *_handle_mmu_fault and *_get_phys_page_debug
functions, using common code for ppc_cpu_tlb_fill and
ppc_cpu_get_phys_page_debug.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210621125115.67717-9-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-07-09 10:38:19 +10:00
Richard Henderson
077a370499 target/ppc: Use bool success for ppc_radix64_xlate
Instead of returning non-zero for failure, return true for success.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210621125115.67717-5-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-07-09 10:38:19 +10:00
Richard Henderson
42a611240e target/ppc: Push real-mode handling into ppc_radix64_xlate
This removes some incomplete duplication between
ppc_radix64_handle_mmu_fault and ppc_radix64_get_phys_page_debug.
The former was correct wrt SPR_HRMOR and the latter was not.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210621125115.67717-4-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-07-09 10:38:19 +10:00
Richard Henderson
1b4d1cb31a target/ppc: Use MMUAccessType with *_handle_mmu_fault
These changes were waiting until we didn't need to match
the function type of PowerPCCPUClass.handle_mmu_fault.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210621125115.67717-3-bruno.larsen@eldorado.org.br>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-07-09 10:38:18 +10:00
Bruno Larsen (billionai)
f2fac71d81 target/ppc: removed unnecessary inclusion of helper-proto.h
These files included helper-proto.h, but didn't use or declare any
helpers, so the #include has been removed

Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210521201759.85475-6-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-06-03 13:22:06 +10:00
Richard Henderson
13c5fdbac6 target/ppc: Use MMUAccessType in mmu-radix64.c
We must leave the 'int rwx' parameter to ppc_radix64_handle_mmu_fault
for now, but will clean that up later.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210518201146.794854-3-richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-05-19 12:50:47 +10:00
Richard Henderson
182357dbb6 target/ppc: Introduce prot_for_access_type
Use this in the three places we currently have a local array
indexed by rwx (which happens to have the same values).
The types will match up correctly with additional changes.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210518201146.794854-2-richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-05-19 12:50:47 +10:00
Chetan Pant
6bd039cdbe powerpc tcg: Fix Lesser GPL version number
There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "Lesser GPL version 2" with
"Lesser GPL version 2.1" in comment section.

Signed-off-by: Chetan Pant <chetan4windows@gmail.com>
Message-Id: <20201019061126.3102-1-chetan4windows@gmail.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2020-11-15 16:38:50 +01:00
Greg Kurz
47e112c4dd target/ppc: Fix argument to ppc_radix64_partition_scoped_xlate() again
The penultimate argument of function ppc_radix64_partition_scoped_xlate()
has the bool type.

Fixes: d04ea940c5 "target/ppc: Add support for Radix partition-scoped translation"
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159051003729.407106.10610703877543955831.stgit@bahia.lan>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-27 15:29:36 +10:00
Greg Kurz
e606a55801 target/ppc: Don't update radix PTE R/C bits with gdbstub
gdbstub shouldn't silently change guest visible state when doing address
translation. Since the R/C bits can only be updated when handling a MMU
fault, let's reuse the cause_excp flag and rename it to guest_visible.
While here drop a not very useful comment.

This was found while reading the code. I could verify that this affects
both powernv and pseries, but I failed to observe any actual bug.

Fixes: d04ea940c5 "target/ppc: Add support for Radix partition-scoped translation"
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <158941063899.240484.2778628492106387793.stgit@bahia.lan>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-27 15:29:36 +10:00
Greg Kurz
31efae9958 target/ppc: Fix arguments to ppc_radix64_partition_scoped_xlate()
The last two arguments have the bool type. Also, we shouldn't raise an
exception when using gdbstub.

This was found while reading the code. Since it only affects the powernv
machine, I didn't dig further to find an actual bug.

Fixes: d04ea940c5 "target/ppc: Add support for Radix partition-scoped translation"
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <158941063281.240484.9114539141307005992.stgit@bahia.lan>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-27 15:29:36 +10:00
Greg Kurz
b577031cf2 target/ppc: Add missing braces in ppc_radix64_partition_scoped_xlate()
As per CODING_STYLE.

Fixes: d04ea940c5 "target/ppc: Add support for Radix partition-scoped translation"
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <158941062665.240484.2663106458734800894.stgit@bahia.lan>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-27 15:29:36 +10:00
Greg Kurz
7caee782e9 target/ppc: Don't initialize some local variables in ppc_radix64_xlate()
It is the job of the ppc_radix64_get_fully_qualified_addr() function
which is called at the beginning of ppc_radix64_xlate() to set both
lpid *and* pid. It doesn't buy us anything to initialize them first.

Worse, a bug in ppc_radix64_get_fully_qualified_addr(), eg. failing to
set either lpid or pid, would be undetectable by static analysis tools
like coverity.

Some recent versions of gcc (eg. gcc-9.3.1-2.fc30) may still think
that lpid or pid is used uninitialized though, so this also adds
default cases in the switch statements to make it clear this cannot
happen.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <158941062048.240484.9693581559252337111.stgit@bahia.lan>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-27 15:29:36 +10:00
Greg Kurz
1830422611 target/ppc: Pass const pointer to ppc_radix64_get_fully_qualified_addr()
This doesn't require write access to the CPU registers.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <158941061434.240484.10700096396035994133.stgit@bahia.lan>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-27 15:29:36 +10:00
Cédric Le Goater
d04ea940c5 target/ppc: Add support for Radix partition-scoped translation
The Radix tree translation model currently supports process-scoped
translation for the PowerNV machine (Hypervisor mode) and for the
pSeries machine (Guest mode). Guests running under an emulated
Hypervisor (PowerNV machine) require a new type of Radix translation,
called partition-scoped, which is missing today.

The Radix tree translation is a 2 steps process. The first step,
process-scoped translation, converts an effective Address to a guest
real address, and the second step, partition-scoped translation,
converts a guest real address to a host real address.

There are difference cases to covers :

* Hypervisor real mode access: no Radix translation.

* Hypervisor or host application access (quadrant 0 and 3) with
  relocation on: process-scoped translation.

* Guest OS real mode access: only partition-scoped translation.

* Guest OS real or guest application access (quadrant 0 and 3) with
  relocation on: both process-scoped translation and partition-scoped
  translations.

* Hypervisor access in quadrant 1 and 2 with relocation on: both
  process-scoped translation and partition-scoped translations.

The radix tree partition-scoped translation is performed using tables
pointed to by the first double-word of the Partition Table Entries and
process-scoped translation uses tables pointed to by the Process Table
Entries (second double-word of the Partition Table Entries).

Both partition-scoped and process-scoped translations process are
identical and thus the radix tree traversing code is largely reused.
However, errors in partition-scoped translations generate hypervisor
exceptions.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20200403140056.59465-5-clg@kaod.org>
[dwg: Fixup from Greg Kurz folded in]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-07 11:10:50 +10:00
Cédric Le Goater
6bffd48b9e target/ppc: Rework ppc_radix64_walk_tree() for partition-scoped translation
The ppc_radix64_walk_tree() routine walks through the nested radix
tables to look for a PTE.

Split it in two and introduce a new routine ppc_radix64_next_level()
which we will use for partition-scoped Radix translation when
translating the process tree addresses. The prototypes are slightly
change to use a 'AddressSpace *' parameter, instead of a 'PowerPCCPU *'
which is not required, and to return an error code instead of a PTE
value. It clarifies error handling in the callers.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20200403140056.59465-4-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-07 11:10:50 +10:00
Cédric Le Goater
522ad21875 target/ppc: Extend ppc_radix64_check_prot() with a 'partition_scoped' bool
This prepares ground for partition-scoped Radix translation.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200403140056.59465-3-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-07 11:10:50 +10:00
Cédric Le Goater
d92baf00aa target/ppc: Introduce ppc_radix64_xlate() for Radix tree translation
This is moving code under a new ppc_radix64_xlate() routine shared by
the MMU Radix page fault handler and the 'get_phys_page_debug' PPC
callback. The difference being that 'get_phys_page_debug' does not
generate exceptions.

The specific part of process-scoped Radix translation is moved under
ppc_radix64_process_scoped_xlate() in preparation of the future support
for partition-scoped Radix translation. Routines raising the exceptions
now take a 'cause_excp' bool to cover the 'get_phys_page_debug' case.

It should be functionally equivalent.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20200403140056.59465-2-clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-07 11:10:50 +10:00
Cédric Le Goater
beae5e9dc6 target/ppc: Assert if HV mode is set when running under a pseries machine
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20200330094946.24678-4-clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-07 11:10:50 +10:00
Cédric Le Goater
f208ec7160 target/ppc: Introduce a relocation bool in ppc_radix64_handle_mmu_fault()
It will ease the introduction of new routines for partition-scoped
Radix translation.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20200330094946.24678-3-clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-07 11:10:50 +10:00
Suraj Jitindar Singh
933abb9c23 target/ppc: Enforce that the root page directory size must be at least 5
According to the ISA the root page directory size of a radix tree for
either process- or partition-scoped translation must be >= 5.

Thus add this to the list of conditions checked when validating the
partition table entry in validate_pate();

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20200330094946.24678-2-clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-07 11:10:50 +10:00
Cédric Le Goater
a9ec49af3b ppc/pnv: Add support for HRMOR on Radix host
When in HV mode, if EA[0] is 0, the Hypervisor Offset Real Mode
Register controls the access.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20200127144154.10170-2-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-02-02 14:07:57 +11:00
Benjamin Herrenschmidt
24b5e0a5ce target/ppc: Don't check UPRT in radix mode when in HV real mode
It appears that during kexec, we run for a while in hypervisor
real mode with LPCR:HR set and LPCR:UPRT clear, which trips
the assertion in ppc_radix64_handle_mmu_fault().

First this shouldn't be an assertion, it's a guest error.

Then we shouldn't be checking these things in hypervisor real
mode (or in virtual hypervisor guest real mode which is similar)
as the real HW won't use those LPCR bits in those cases anyway,
so technically it's ok to have this discrepancy.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190411080004.8690-2-clg@kaod.org>
[dwg: Fix for 32-bit builds]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-04-26 11:37:57 +10:00
Benjamin Herrenschmidt
539c6e7358 target/ppc: Basic POWER9 bare-metal radix MMU support
No guest support yet

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190215170029.15641-13-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-26 09:21:25 +11:00
Benjamin Herrenschmidt
79825f4d58 target/ppc: Rename PATB/PATBE -> PATE
That "b" means "base address" and thus shouldn't be in the name
of actual entries and related constants.

This patch keeps the synthetic patb_entry field of the spapr
virtual hypervisor unchanged until I figure out if that has
an impact on the migration stream.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190215170029.15641-11-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-26 09:21:25 +11:00
Markus Armbruster
e688df6bc4 Include qapi/error.h exactly where needed
This cleanup makes the number of objects depending on qapi/error.h
drop from 1910 (out of 4743) to 1612 in my "build everything" tree.

While there, separate #include from file comment with a blank line,
and drop a useless comment on why qemu/osdep.h is included first.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-5-armbru@redhat.com>
[Semantic conflict with commit 34e304e975 resolved, OSX breakage fixed]
2018-02-09 13:50:17 +01:00
Suraj Jitindar Singh
95cb065776 target/ppc: Add debug function for radix mmu translation
In target/ppc/mmu-hash64.c there already exists the function
ppc_hash64_get_phys_page_debug() to get the physical (real) address for
a given effective address in hash mode.

Implement the function ppc_radix64_get_phys_page_debug() to allow a real
address to be obtained for a given effective address in radix mode.
This is used when a debugger is attached to qemu.

Previously we just had a comment saying this is unimplemented which then
fell through to the default case and caused an abort due to
unrecognised mmu model as the default had no case for the V3 mmu, which
was misleading at best.

We reuse ppc_radix64_walk_tree() which is used by the radix fault
handler since the process of walking the radix tree is identical.

Reported-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-07-11 11:04:02 +10:00
Suraj Jitindar Singh
6a042827b6 target/ppc: Refactor tcg radix mmu code
The mmu-radix64.c file implements functions to enable the radix mmu
emulation in tcg mode. There is a function ppc_radix64_walk_tree() which
performs the radix tree walk and also implicitly checks the pte
protection.

Move the protection checking of the pte from the ppc_radix64_walk_tree()
function into the caller. This means the ppc_radix64_walk_tree() function
can be used without protection checking which is useful for debugging.

ppc_radix64_walk_tree() no longer needs to take the rwx and prot variables.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-07-11 11:04:02 +10:00
Suraj Jitindar Singh
35068bd15e target/ppc: Fix return value in tcg radix mmu fault handler
The mmu fault handler should return 0 if it was able to successfully
handle the fault and a positive value otherwise.

Currently the tcg radix mmu fault handler will return 1 after
successfully handling a fault in virtual mode. This is incorrect
so fix it so that it returns 0 in this case.

The handler already correctly returns 0 when a fault was handled
in real mode and 1 if an interrupt was generated.

Fixes: d5fee0bbe6 ("target/ppc: Implement ISA V3.00 radix page fault handler")

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-06-30 14:03:31 +10:00
Suraj Jitindar Singh
d5fee0bbe6 target/ppc: Implement ISA V3.00 radix page fault handler
ISA V3.00 introduced a new radix mmu model. Implement the page fault
handler for this so we can run a tcg guest in radix mode and perform
address translation correctly.

In real mode (mmu turned off) addresses are masked to remove the top
4 bits and then are subject to partition scoped translation, since we only
support pseries at this stage it is only necessary to perform the masking
and then we're done.

In virtual mode (mmu turned on) address translation if performed as
follows:

1. Use the quadrant to determine the fully qualified address.

The fully qualified address is defined as the combination of the effective
address, the effective logical partition id (LPID) and the effective
process id (PID). Based on the quadrant (EA63:62) we set the pid and lpid
like so:

quadrant 0: lpid = LPIDR, pid = PIDR
quadrant 1: HV only (not allowed in pseries)
quadrant 2: HV only (not allowed in pseries)
quadrant 3: lpid = LPIDR, pid = 0

If we can't get the fully qualified address we raise a segment interrupt.

2. Find the guest radix tree

We ask the virtual hypervisor for the partition table which was registered
with H_REGISTER_PROC_TBL which points us to the process table in guest
memory. We then index this table by pid to get the process table entry
which points us to the appropriate radix tree to translate the address.

If the process table isn't big enough to contain an entry for the current
pid then we raise a storage interrupt.

3. Walk the radix tree

Next we walk the radix tree where each level is a table of page directory
entries indexed by some number of bits from the effective address, where
the number of bits is determined by the table size. We continue to walk
the tree (while entries are valid and the table is of minimum size) until
we reach a table of page table entries, indicated by having the leaf bit
set. The appropriate pte is then checked for sufficient access permissions,
the reference and change bits are updated and the real address is
calculated from the real page number bits of the pte and the low bits of
the effective address.

If we can't find an entry or can't access the entry bacause of permissions
then we raise a storage interrupt.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
[dwg: Add missing parentheses to macro]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-05-11 09:45:15 +10:00