| /* SPDX-License-Identifier: GPL-2.0-only */ |
| #include <asm/asm-offsets.h> |
| #include <asm/cache.h> |
| #include <asm/exception-64s.h> |
| #include <asm/kvm_asm.h> |
| #include <asm/kvm_book3s_asm.h> |
| #include <asm/ppc_asm.h> |
| #include <asm/reg.h> |
| |
| /* |
| * These are branched to from interrupt handlers in exception-64s.S which set |
| * IKVM_REAL or IKVM_VIRT, if HSTATE_IN_GUEST was found to be non-zero. |
| */ |
| .global kvmppc_hcall |
| .balign IFETCH_ALIGN_BYTES |
| kvmppc_hcall: |
| |
| .global kvmppc_interrupt |
| .balign IFETCH_ALIGN_BYTES |
| kvmppc_interrupt: |
| /* |
| * Register contents: |
| * R12 = (guest CR << 32) | interrupt vector |
| * R13 = PACA |
| * guest R12 saved in shadow VCPU SCRATCH0 |
| * guest R13 saved in SPRN_SCRATCH0 |
| */ |
| std r9,HSTATE_SCRATCH2(r13) |
| lbz r9,HSTATE_IN_GUEST(r13) |
| cmpwi r9,KVM_GUEST_MODE_SKIP |
| beq- .Lmaybe_skip |
| .Lno_skip: |
| #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE |
| cmpwi r9,KVM_GUEST_MODE_HOST_HV |
| beq kvmppc_bad_host_intr |
| #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE |
| cmpwi r9,KVM_GUEST_MODE_GUEST |
| ld r9,HSTATE_SCRATCH2(r13) |
| beq kvmppc_interrupt_pr |
| #endif |
| b kvmppc_interrupt_hv |
| #else |
| ld r9,HSTATE_SCRATCH2(r13) |
| b kvmppc_interrupt_pr |
| #endif |
| |
| /* |
| * "Skip" interrupts are part of a trick KVM uses a with hash guests to load |
| * the faulting instruction in guest memory from the the hypervisor without |
| * walking page tables. |
| * |
| * When the guest takes a fault that requires the hypervisor to load the |
| * instruction (e.g., MMIO emulation), KVM is running in real-mode with HV=1 |
| * and the guest MMU context loaded. It sets KVM_GUEST_MODE_SKIP, and sets |
| * MSR[DR]=1 while leaving MSR[IR]=0, so it continues to fetch HV instructions |
| * but loads and stores will access the guest context. This is used to load |
| * the faulting instruction using the faulting guest effective address. |
| * |
| * However the guest context may not be able to translate, or it may cause a |
| * machine check or other issue, which results in a fault in the host |
| * (even with KVM-HV). |
| * |
| * These faults come here because KVM_GUEST_MODE_SKIP was set, so if they |
| * are (or are likely) caused by that load, the instruction is skipped by |
| * just returning with the PC advanced +4, where it is noticed the load did |
| * not execute and it goes to the slow path which walks the page tables to |
| * read guest memory. |
| */ |
| .Lmaybe_skip: |
| cmpwi r12,BOOK3S_INTERRUPT_MACHINE_CHECK |
| beq 1f |
| cmpwi r12,BOOK3S_INTERRUPT_DATA_STORAGE |
| beq 1f |
| cmpwi r12,BOOK3S_INTERRUPT_DATA_SEGMENT |
| beq 1f |
| #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE |
| /* HSRR interrupts get 2 added to interrupt number */ |
| cmpwi r12,BOOK3S_INTERRUPT_H_DATA_STORAGE | 0x2 |
| beq 2f |
| #endif |
| b .Lno_skip |
| 1: mfspr r9,SPRN_SRR0 |
| addi r9,r9,4 |
| mtspr SPRN_SRR0,r9 |
| ld r12,HSTATE_SCRATCH0(r13) |
| ld r9,HSTATE_SCRATCH2(r13) |
| GET_SCRATCH0(r13) |
| RFI_TO_KERNEL |
| #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE |
| 2: mfspr r9,SPRN_HSRR0 |
| addi r9,r9,4 |
| mtspr SPRN_HSRR0,r9 |
| ld r12,HSTATE_SCRATCH0(r13) |
| ld r9,HSTATE_SCRATCH2(r13) |
| GET_SCRATCH0(r13) |
| HRFI_TO_KERNEL |
| #endif |