History log of /arch/powerpc/kvm/book3s_rmhandlers.S
Revision Date Author Comments
02143947603fe90237a0423d34dd8943de229f78 23-Jul-2011 Paul Mackerras <paulus@samba.org> KVM: PPC: book3s_pr: Simplify transitions between virtual and real mode

This simplifies the way that the book3s_pr makes the transition to
real mode when entering the guest. We now call kvmppc_entry_trampoline
(renamed from kvmppc_rmcall) in the base kernel using a normal function
call instead of doing an indirect call through a pointer in the vcpu.
If kvm is a module, the module loader takes care of generating a
trampoline as it does for other calls to functions outside the module.

kvmppc_entry_trampoline then disables interrupts and jumps to
kvmppc_handler_trampoline_enter in real mode using an rfi[d].
That then uses the link register as the address to return to
(potentially in module space) when the guest exits.

This also simplifies the way that we call the Linux interrupt handler
when we exit the guest due to an external, decrementer or performance
monitor interrupt. Instead of turning on the MMU, then deciding that
we need to call the Linux handler and turning the MMU back off again,
we now go straight to the handler at the point where we would turn the
MMU on. The handler will then return to the virtual-mode code
(potentially in the module).

Along the way, this moves the setting and clearing of the HID5 DCBZ32
bit into real-mode interrupts-off code, and also makes sure that
we clear the MSR[RI] bit before loading values into SRR0/1.

The net result is that we no longer need any code addresses to be
stored in vcpu->arch.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
177339d7f7c99a25ecfdb6baeea6a2508fb2349f 23-Jul-2011 Paul Mackerras <paulus@samba.org> KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S separately

This makes arch/powerpc/kvm/book3s_rmhandlers.S and
arch/powerpc/kvm/book3s_hv_rmhandlers.S be assembled as
separate compilation units rather than having them #included in
arch/powerpc/kernel/exceptions-64s.S. We no longer have any
conditional branches between the exception prologs in
exceptions-64s.S and the KVM handlers, so there is no need to
keep their contents close together in the vmlinux image.

In their current location, they are using up part of the limited
space between the first-level interrupt handlers and the firmware
NMI data area at offset 0x7000, and with some kernel configurations
this area will overflow (e.g. allyesconfig), leading to an
"attempt to .org backwards" error when compiling exceptions-64s.S.

Moving them out requires that we add some #includes that the
book3s_{,hv_}rmhandlers.S code was previously getting implicitly
via exceptions-64s.S.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
3c42bf8a717cb636e0ed2ed77194669e2ac3ed56 29-Jun-2011 Paul Mackerras <paulus@samba.org> KVM: PPC: Split host-state fields out of kvmppc_book3s_shadow_vcpu

There are several fields in struct kvmppc_book3s_shadow_vcpu that
temporarily store bits of host state while a guest is running,
rather than anything relating to the particular guest or vcpu.
This splits them out into a new kvmppc_host_state structure and
modifies the definitions in asm-offsets.c to suit.

On 32-bit, we have a kvmppc_host_state structure inside the
kvmppc_book3s_shadow_vcpu since the assembly code needs to be able
to get to them both with one pointer. On 64-bit they are separate
fields in the PACA. This means that on 64-bit we don't need to
copy the kvmppc_host_state in and out on vcpu load/unload, and
in future will mean that the book3s_hv code doesn't need a
shadow_vcpu struct in the PACA at all. That does mean that we
have to be careful not to rely on any values persisting in the
hstate field of the paca across any point where we could block
or get preempted.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
b01c8b54a1a271c0fc4243845927fe1d250767a3 29-Jun-2011 Paul Mackerras <paulus@samba.org> powerpc, KVM: Rework KVM checks in first-level interrupt handlers

Instead of branching out-of-line with the DO_KVM macro to check if we
are in a KVM guest at the time of an interrupt, this moves the KVM
check inline in the first-level interrupt handlers. This speeds up
the non-KVM case and makes sure that none of the interrupt handlers
are missing the check.

Because the first-level interrupt handlers are now larger, some things
had to be move out of line in exceptions-64s.S.

This all necessitated some minor changes to the interrupt entry code
in KVM. This also streamlines the book3s_32 KVM test.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
a22a2daccfa3ade5cdd9ef1e8a05cf1e6ffca42b 07-Jun-2011 Alexander Graf <agraf@suse.de> KVM: PPC: Resolve real-mode handlers through function exports

Up until now, Book3S KVM had variables stored in the kernel that a kernel module
or the kvm code in the kernel could read from to figure out where some real mode
helper functions are located.

This is all unnecessary. The high bits of the EA get ignore in real mode, so we
can just use the pointer as is. Also, it's a lot easier on relocations when we
use the normal way of resolving the address to a function, instead of jumping
through hoops.

This patch fixes compilation with CONFIG_RELOCATABLE=y.

Signed-off-by: Alexander Graf <agraf@suse.de>
593adf317cf165f7c66facf2285db9d4befbd1c0 11-May-2011 Paul Mackerras <paulus@samba.org> powerpc/kvm: Fix the build for 32-bit Book 3S (classic) processors

Commits a5d4f3ad3a ("powerpc: Base support for exceptions using
HSRR0/1") and 673b189a2e ("powerpc: Always use SPRN_SPRG_HSCRATCH0
when running in HV mode") cause compile and link errors for 32-bit
classic Book 3S processors when KVM is enabled. This fixes these
errors.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
673b189a2e3353061fa8c49515d1014dab6ad9b9 05-Apr-2011 Paul Mackerras <paulus@samba.org> powerpc: Always use SPRN_SPRG_HSCRATCH0 when running in HV mode

This uses feature sections to arrange that we always use HSPRG1
as the scratch register in the interrupt entry code rather than
SPRG2 when we're running in hypervisor mode on POWER7. This will
ensure that we don't trash the guest's SPRG2 when we are running
KVM guests. To simplify the code, we define GET_SCRATCH0() and
SET_SCRATCH0() macros like the GET_PACA/SET_PACA macros.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
a5d4f3ad3a28cf046836b9bfae61d532b8f77036 05-Apr-2011 Benjamin Herrenschmidt <benh@kernel.crashing.org> powerpc: Base support for exceptions using HSRR0/1

Pass the register type to the prolog, also provides alternate "HV"
version of hardware interrupt (0x500) and adjust LPES accordingly

We tag those interrupts by setting bit 0x2 in the trap number

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2dd60d79e0202628a47af9812a84d502cc63628c 20-Jan-2011 Benjamin Herrenschmidt <benh@kernel.crashing.org> powerpc: In HV mode, use HSPRG0 for PACA

When running in Hypervisor mode (arch 2.06 or later), we store the PACA
in HSPRG0 instead of SPRG1. The architecture specifies that SPRGs may be
lost during a "nap" power management operation (though they aren't
currently on POWER7) and this enables use of SPRG1 by KVM guests.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2b05d71fefc3b83e686bead355c6d35e440c4261 29-Jul-2010 Alexander Graf <agraf@suse.de> KVM: PPC: Make long relocations be ulong

On Book3S KVM we directly expose some asm pointers to C code as
variables. These need to be relocated and thus break on relocatable
kernels.

To make sure we can at least build, let's mark them as long instead
of u32 where 64bit relocations don't work.

This fixes the following build error:

WARNING: 2 bad relocations^M
> c000000000008590 R_PPC64_ADDR32 .text+0x4000000000008460^M
> c000000000008594 R_PPC64_ADDR32 .text+0x4000000000008598^M

Please keep in mind that actually using KVM on a relocated kernel
might still break. This only fixes the compile problem.

Reported-by: Subrata Modak <subrata@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
0e677903878ef90e09a45507255c0b1e36166064 29-Jul-2010 Alexander Graf <agraf@suse.de> KVM: PPC: Use MSR_DR for external load_up

Book3S_32 requires MSR_DR to be disabled during load_up_xxx while on Book3S_64
it's supposed to be enabled. I misread the code and disabled it in both cases,
potentially breaking the PS3 which has a really small RMA.

This patch makes KVM work on the PS3 again.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
07b0907db19d28dc74e7927d565655690b96daf7 16-Apr-2010 Alexander Graf <agraf@suse.de> KVM: PPC: Add Book3S compatibility code

Some code we had so far required defines and had code that was completely
Book3S_64 specific. Since we now opened book3s.c to Book3S_32 too, we need
to take care of these pieces.

So let's add some minor code where it makes sense to not go the Book3S_64
code paths and add compat defines on others.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
53e5b8bbbd0d0305234b2cfeae400183db98f993 16-Apr-2010 Alexander Graf <agraf@suse.de> KVM: PPC: Make SLB switching code the new segment framework

We just introduced generic segment switching code that only needs to call
small macros to do the actual switching, but keeps most of the entry / exit
code generic.

So let's move the SLB switching code over to use this new mechanism.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
8c3a4e0b673ba8b274399f575dc803a89a953a66 16-Apr-2010 Alexander Graf <agraf@suse.de> KVM: PPC: Make real mode handler generic

The real mode handler code was originally writen for 64 bit Book3S only.
But since we not add 32 bit functionality too, we need to make some tweaks
to it.

This patch basically combines using the "long" access defines and using
fields from the shadow VCPU we just moved there.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2191d657c9eaa4c444c33e014199ed9de1ac339d 16-Apr-2010 Alexander Graf <agraf@suse.de> KVM: PPC: Name generic 64-bit code generic

We have quite some code that can be used by Book3S_32 and Book3S_64 alike,
so let's call it "Book3S" instead of "Book3S_64", so we can later on
use it from the 32 bit port too.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>