diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv_rmhandlers.S')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rmhandlers.S | 183 |
1 files changed, 102 insertions, 81 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 975655573844..7cc924b5eea2 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -221,6 +221,13 @@ kvmppc_primary_no_guest: li r3, 0 /* Don't wake on privileged (OS) doorbell */ b kvm_do_nap +/* + * kvm_novcpu_wakeup + * Entered from kvm_start_guest if kvm_hstate.napping is set + * to NAPPING_NOVCPU + * r2 = kernel TOC + * r13 = paca + */ kvm_novcpu_wakeup: ld r1, HSTATE_HOST_R1(r13) ld r5, HSTATE_KVM_VCORE(r13) @@ -230,6 +237,13 @@ kvm_novcpu_wakeup: /* check the wake reason */ bl kvmppc_check_wake_reason + /* + * Restore volatile registers since we could have called + * a C routine in kvmppc_check_wake_reason. + * r5 = VCORE + */ + ld r5, HSTATE_KVM_VCORE(r13) + /* see if any other thread is already exiting */ lwz r0, VCORE_ENTRY_EXIT(r5) cmpwi r0, 0x100 @@ -322,6 +336,11 @@ kvm_start_guest: /* Check the wake reason in SRR1 to see why we got here */ bl kvmppc_check_wake_reason + /* + * kvmppc_check_wake_reason could invoke a C routine, but we + * have no volatile registers to restore when we return. + */ + cmpdi r3, 0 bge kvm_no_guest @@ -881,6 +900,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) cmpwi r3, 512 /* 1 microsecond */ blt hdec_soon +deliver_guest_interrupt: ld r6, VCPU_CTR(r4) ld r7, VCPU_XER(r4) @@ -895,7 +915,6 @@ kvmppc_cede_reentry: /* r4 = vcpu, r13 = paca */ mtspr SPRN_SRR0, r6 mtspr SPRN_SRR1, r7 -deliver_guest_interrupt: /* r11 = vcpu->arch.msr & ~MSR_HV */ rldicl r11, r11, 63 - MSR_HV_LG, 1 rotldi r11, r11, 1 + MSR_HV_LG @@ -1155,10 +1174,54 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) * set, we know the host wants us out so let's do it now */ bl kvmppc_read_intr + + /* + * Restore the active volatile registers after returning from + * a C function. + */ + ld r9, HSTATE_KVM_VCPU(r13) + li r12, BOOK3S_INTERRUPT_EXTERNAL + + /* + * kvmppc_read_intr return codes: + * + * Exit to host (r3 > 0) + * 1 An interrupt is pending that needs to be handled by the host + * Exit guest and return to host by branching to guest_exit_cont + * + * 2 Passthrough that needs completion in the host + * Exit guest and return to host by branching to guest_exit_cont + * However, we also set r12 to BOOK3S_INTERRUPT_HV_RM_HARD + * to indicate to the host to complete handling the interrupt + * + * Before returning to guest, we check if any CPU is heading out + * to the host and if so, we head out also. If no CPUs are heading + * check return values <= 0. + * + * Return to guest (r3 <= 0) + * 0 No external interrupt is pending + * -1 A guest wakeup IPI (which has now been cleared) + * In either case, we return to guest to deliver any pending + * guest interrupts. + * + * -2 A PCI passthrough external interrupt was handled + * (interrupt was delivered directly to guest) + * Return to guest to deliver any pending guest interrupts. + */ + + cmpdi r3, 1 + ble 1f + + /* Return code = 2 */ + li r12, BOOK3S_INTERRUPT_HV_RM_HARD + stw r12, VCPU_TRAP(r9) + b guest_exit_cont + +1: /* Return code <= 1 */ cmpdi r3, 0 bgt guest_exit_cont - /* Check if any CPU is heading out to the host, if so head out too */ + /* Return code <= 0 */ 4: ld r5, HSTATE_KVM_VCORE(r13) lwz r0, VCORE_ENTRY_EXIT(r5) cmpwi r0, 0x100 @@ -2213,10 +2276,20 @@ END_FTR_SECTION_IFSET(CPU_FTR_TM) ld r29, VCPU_GPR(R29)(r4) ld r30, VCPU_GPR(R30)(r4) ld r31, VCPU_GPR(R31)(r4) - + /* Check the wake reason in SRR1 to see why we got here */ bl kvmppc_check_wake_reason + /* + * Restore volatile registers since we could have called a + * C routine in kvmppc_check_wake_reason + * r4 = VCPU + * r3 tells us whether we need to return to host or not + * WARNING: it gets checked further down: + * should not modify r3 until this check is done. + */ + ld r4, HSTATE_KVM_VCPU(r13) + /* clear our bit in vcore->napping_threads */ 34: ld r5,HSTATE_KVM_VCORE(r13) lbz r7,HSTATE_PTID(r13) @@ -2230,7 +2303,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_TM) li r0,0 stb r0,HSTATE_NAPPING(r13) - /* See if the wake reason means we need to exit */ + /* See if the wake reason saved in r3 means we need to exit */ stw r12, VCPU_TRAP(r4) mr r9, r4 cmpdi r3, 0 @@ -2297,10 +2370,14 @@ machine_check_realmode: * 0 if nothing needs to be done * 1 if something happened that needs to be handled by the host * -1 if there was a guest wakeup (IPI or msgsnd) + * -2 if we handled a PCI passthrough interrupt (returned by + * kvmppc_read_intr only) * * Also sets r12 to the interrupt vector for any interrupt that needs * to be handled now by the host (0x500 for external interrupt), or zero. - * Modifies r0, r6, r7, r8. + * Modifies all volatile registers (since it may call a C function). + * This routine calls kvmppc_read_intr, a C function, if an external + * interrupt is pending. */ kvmppc_check_wake_reason: mfspr r6, SPRN_SRR1 @@ -2310,8 +2387,7 @@ FTR_SECTION_ELSE rlwinm r6, r6, 45-31, 0xe /* P7 wake reason field is 3 bits */ ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_207S) cmpwi r6, 8 /* was it an external interrupt? */ - li r12, BOOK3S_INTERRUPT_EXTERNAL - beq kvmppc_read_intr /* if so, see what it was */ + beq 7f /* if so, see what it was */ li r3, 0 li r12, 0 cmpwi r6, 6 /* was it the decrementer? */ @@ -2350,83 +2426,28 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) li r3, 1 blr -/* - * Determine what sort of external interrupt is pending (if any). - * Returns: - * 0 if no interrupt is pending - * 1 if an interrupt is pending that needs to be handled by the host - * -1 if there was a guest wakeup IPI (which has now been cleared) - * Modifies r0, r6, r7, r8, returns value in r3. - */ -kvmppc_read_intr: - /* see if a host IPI is pending */ - li r3, 1 - lbz r0, HSTATE_HOST_IPI(r13) - cmpwi r0, 0 - bne 1f + /* external interrupt - create a stack frame so we can call C */ +7: mflr r0 + std r0, PPC_LR_STKOFF(r1) + stdu r1, -PPC_MIN_STKFRM(r1) + bl kvmppc_read_intr + nop + li r12, BOOK3S_INTERRUPT_EXTERNAL + cmpdi r3, 1 + ble 1f - /* Now read the interrupt from the ICP */ - ld r6, HSTATE_XICS_PHYS(r13) - li r7, XICS_XIRR - cmpdi r6, 0 - beq- 1f - lwzcix r0, r6, r7 /* - * Save XIRR for later. Since we get in in reverse endian on LE - * systems, save it byte reversed and fetch it back in host endian. - */ - li r3, HSTATE_SAVED_XIRR - STWX_BE r0, r3, r13 -#ifdef __LITTLE_ENDIAN__ - lwz r3, HSTATE_SAVED_XIRR(r13) -#else - mr r3, r0 -#endif - rlwinm. r3, r3, 0, 0xffffff - sync - beq 1f /* if nothing pending in the ICP */ - - /* We found something in the ICP... - * - * If it's not an IPI, stash it in the PACA and return to - * the host, we don't (yet) handle directing real external - * interrupts directly to the guest + * Return code of 2 means PCI passthrough interrupt, but + * we need to return back to host to complete handling the + * interrupt. Trap reason is expected in r12 by guest + * exit code. */ - cmpwi r3, XICS_IPI /* if there is, is it an IPI? */ - bne 42f - - /* It's an IPI, clear the MFRR and EOI it */ - li r3, 0xff - li r8, XICS_MFRR - stbcix r3, r6, r8 /* clear the IPI */ - stwcix r0, r6, r7 /* EOI it */ - sync - - /* We need to re-check host IPI now in case it got set in the - * meantime. If it's clear, we bounce the interrupt to the - * guest - */ - lbz r0, HSTATE_HOST_IPI(r13) - cmpwi r0, 0 - bne- 43f - - /* OK, it's an IPI for us */ - li r12, 0 - li r3, -1 -1: blr - -42: /* It's not an IPI and it's for the host. We saved a copy of XIRR in - * the PACA earlier, it will be picked up by the host ICP driver - */ - li r3, 1 - b 1b - -43: /* We raced with the host, we need to resend that IPI, bummer */ - li r0, IPI_PRIORITY - stbcix r0, r6, r8 /* set the IPI */ - sync - li r3, 1 - b 1b + li r12, BOOK3S_INTERRUPT_HV_RM_HARD +1: + ld r0, PPC_MIN_STKFRM+PPC_LR_STKOFF(r1) + addi r1, r1, PPC_MIN_STKFRM + mtlr r0 + blr /* * Save away FP, VMX and VSX registers. |
