summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kvm/tm.S
AgeCommit message (Collapse)AuthorFilesLines
2018-10-09KVM: PPC: Book3S: Rework TM save/restore code and make it C-callablePaul Mackerras1-114/+136
This adds a parameter to __kvmppc_save_tm and __kvmppc_restore_tm which allows the caller to indicate whether it wants the nonvolatile register state to be preserved across the call, as required by the C calling conventions. This parameter being non-zero also causes the MSR bits that enable TM, FP, VMX and VSX to be preserved. The condition register and DSCR are now always preserved. With this, kvmppc_save_tm_hv and kvmppc_restore_tm_hv can be called from C code provided the 3rd parameter is non-zero. So that these functions can be called from modules, they now include code to set the TOC pointer (r2) on entry, as they can call other built-in C functions which will assume the TOC to have been set. Also, the fake suspend code in kvmppc_save_tm_hv is modified here to assume that treclaim in fake-suspend state does not modify any registers, which is the case on POWER9. This enables the code to be simplified quite a bit. _kvmppc_save_tm_pr and _kvmppc_restore_tm_pr become much simpler with this change, since they now only need to save and restore TAR and pass 1 for the 3rd argument to __kvmppc_{save,restore}_tm. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-01KVM: PPC: Book3S PR: Support TAR handling for PR KVM HTMSimon Guo1-2/+14
Currently guest kernel doesn't handle TAR facility unavailable and it always runs with TAR bit on. PR KVM will lazily enable TAR. TAR is not a frequent-use register and it is not included in SVCPU struct. Due to the above, the checkpointed TAR val might be a bogus TAR val. To solve this issue, we will make vcpu->arch.fscr tar bit consistent with shadow_fscr when TM is enabled. At the end of emulating treclaim., the correct TAR val need to be loaded into the register if FSCR_TAR bit is on. At the beginning of emulating trechkpt., TAR needs to be flushed so that the right tar val can be copied into tar_tm. Tested with: tools/testing/selftests/powerpc/tm/tm-tar tools/testing/selftests/powerpc/ptrace/ptrace-tm-tar (remove DSCR/PPR related testing). Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-06-01KVM: PPC: Book3S PR: Add C function wrapper for _kvmppc_save/restore_tm()Simon Guo1-2/+92
Currently __kvmppc_save/restore_tm() APIs can only be invoked from assembly function. This patch adds C function wrappers for them so that they can be safely called from C function. Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-06-01KVM: PPC: Book3S PR: Turn on FP/VSX/VMX MSR bits in kvmppc_save_tm()Simon Guo1-0/+2
kvmppc_save_tm() invokes store_fp_state/store_vr_state(). So it is mandatory to turn on FP/VSX/VMX MSR bits for its execution, just like what kvmppc_restore_tm() did. Previously HV KVM has turned the bits on outside of function kvmppc_save_tm(). Now we include this bit change in kvmppc_save_tm() so that the logic is cleaner. And PR KVM can reuse it later. Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-06-01KVM: PPC: Book3S PR: Add guest MSR parameter for ↵Simon Guo1-35/+36
kvmppc_save_tm()/kvmppc_restore_tm() HV KVM and PR KVM need different MSR source to indicate whether treclaim. or trecheckpoint. is necessary. This patch add new parameter (guest MSR) for these kvmppc_save_tm/ kvmppc_restore_tm() APIs: - For HV KVM, it is VCPU_MSR - For PR KVM, it is current host MSR or VCPU_SHADOW_SRR1 This enhancement enables these 2 APIs to be reused by PR KVM later. And the patch keeps HV KVM logic unchanged. This patch also reworks kvmppc_save_tm()/kvmppc_restore_tm() to have a clean ABI: r3 for vcpu and r4 for guest_msr. During kvmppc_save_tm/kvmppc_restore_tm(), the R1 need to be saved or restored. Currently the R1 is saved into HSTATE_HOST_R1. In PR KVM, we are going to add a C function wrapper for kvmppc_save_tm/kvmppc_restore_tm() where the R1 will be incremented with added stackframe and save into HSTATE_HOST_R1. There are several places in HV KVM to load HSTATE_HOST_R1 as R1, and we don't want to bring risk or confusion by TM code. This patch will use HSTATE_SCRATCH2 to save/restore R1 in kvmppc_save_tm/kvmppc_restore_tm() to avoid future confusion, since the r1 is actually a temporary/scratch value to be saved/stored. [paulus@ozlabs.org - rebased on top of 7b0e827c6970 ("KVM: PPC: Book3S HV: Factor fake-suspend handling out of kvmppc_save/restore_tm", 2018-05-30)] Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-31KVM: PPC: Book3S PR: Move kvmppc_save_tm/kvmppc_restore_tm to separate fileSimon Guo1-0/+279
It is a simple patch just for moving kvmppc_save_tm/kvmppc_restore_tm() functionalities to tm.S. There is no logic change. The reconstruct of those APIs will be done in later patches to improve readability. It is for preparation of reusing those APIs on both HV/PR PPC KVM. Some slight change during move the functions includes: - surrounds some HV KVM specific code with CONFIG_KVM_BOOK3S_HV_POSSIBLE for compilation. - use _GLOBAL() to define kvmppc_save_tm/kvmppc_restore_tm() [paulus@ozlabs.org - rebased on top of 7b0e827c6970 ("KVM: PPC: Book3S HV: Factor fake-suspend handling out of kvmppc_save/restore_tm", 2018-05-30)] Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>