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>
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>
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>
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>
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>
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>
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>
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>
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>
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]
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>
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>
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>
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>
