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| author | Paul Mackerras <paulus@ozlabs.org> | 2017-01-30 13:21:51 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-01-31 11:11:51 +0300 |
| commit | 53af3ba2e8195f504d6a3a0667ccb5e7d4c57599 (patch) | |
| tree | 22e84795a9228919fa84c53365e0e701983061e8 /arch/powerpc/kvm/book3s_hv_rmhandlers.S | |
| parent | a29ebeaf5575d03eef178bb87c425a1e46cae1ca (diff) | |
| download | linux-53af3ba2e8195f504d6a3a0667ccb5e7d4c57599.tar.xz | |
KVM: PPC: Book3S HV: Allow guest exit path to have MMU on
If we allow LPCR[AIL] to be set for radix guests, then interrupts from
the guest to the host can be delivered by the hardware with relocation
on, and thus the code path starting at kvmppc_interrupt_hv can be
executed in virtual mode (MMU on) for radix guests (previously it was
only ever executed in real mode).
Most of the code is indifferent to whether the MMU is on or off, but
the calls to OPAL that use the real-mode OPAL entry code need to
be switched to use the virtual-mode code instead. The affected
calls are the calls to the OPAL XICS emulation functions in
kvmppc_read_one_intr() and related functions. We test the MSR[IR]
bit to detect whether we are in real or virtual mode, and call the
opal_rm_* or opal_* function as appropriate.
The other place that depends on the MMU being off is the optimization
where the guest exit code jumps to the external interrupt vector or
hypervisor doorbell interrupt vector, or returns to its caller (which
is __kvmppc_vcore_entry). If the MMU is on and we are returning to
the caller, then we don't need to use an rfid instruction since the
MMU is already on; a simple blr suffices. If there is an external
or hypervisor doorbell interrupt to handle, we branch to the
relocation-on version of the interrupt vector.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv_rmhandlers.S')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rmhandlers.S | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index dcc67a87d688..46c1c1fe55c8 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -148,6 +148,15 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) addi r1, r1, 112 ld r7, HSTATE_HOST_MSR(r13) + /* + * If we came back from the guest via a relocation-on interrupt, + * we will be in virtual mode at this point, which makes it a + * little easier to get back to the caller. + */ + mfmsr r0 + andi. r0, r0, MSR_IR /* in real mode? */ + bne .Lvirt_return + cmpwi cr1, r12, BOOK3S_INTERRUPT_MACHINE_CHECK cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL beq 11f @@ -181,6 +190,26 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) mtspr SPRN_HSRR1, r7 ba 0xe80 + /* Virtual-mode return - can't get here for HMI or machine check */ +.Lvirt_return: + cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL + beq 16f + cmpwi r12, BOOK3S_INTERRUPT_H_DOORBELL + beq 17f + andi. r0, r7, MSR_EE /* were interrupts hard-enabled? */ + beq 18f + mtmsrd r7, 1 /* if so then re-enable them */ +18: mtlr r8 + blr + +16: mtspr SPRN_HSRR0, r8 /* jump to reloc-on external vector */ + mtspr SPRN_HSRR1, r7 + b exc_virt_0x4500_hardware_interrupt + +17: mtspr SPRN_HSRR0, r8 + mtspr SPRN_HSRR1, r7 + b exc_virt_0x4e80_h_doorbell + kvmppc_primary_no_guest: /* We handle this much like a ceded vcpu */ /* put the HDEC into the DEC, since HDEC interrupts don't wake us */ |