We add an extensible CSR emulation framework which is based upon the existing system instruction emulation. This will be useful to upcoming AIA, PMU, Nested and other virtualization features. The CSR emulation framework also has provision to emulate CSR in user space but this will be used only in very specific cases such as AIA IMSIC CSR emulation in user space or vendor specific CSR emulation in user space. By default, all CSRs not handled by KVM RISC-V will be redirected back to Guest VCPU as illegal instruction trap.
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| @@ -270,6 +270,7 @@ struct kvm_xen_exit { · 269 unmodified lines | |||
| 270 | #define KVM_EXIT_X86_BUS_LOCK 33 | 270 | #define KVM_EXIT_X86_BUS_LOCK 33 |
| 271 | #define KVM_EXIT_XEN 34 | 271 | #define KVM_EXIT_XEN 34 |
| 272 | #define KVM_EXIT_RISCV_SBI 35 | 272 | #define KVM_EXIT_RISCV_SBI 35 |
| 273 | #define KVM_EXIT_RISCV_CSR 36 | ||
| 273 | 274 | ||
| 274 | /* For KVM_EXIT_INTERNAL_ERROR */ | 275 | /* For KVM_EXIT_INTERNAL_ERROR */ |
| 275 | /* Emulate instruction failed. */ | 276 | /* Emulate instruction failed. */ |
| @@ -496,6 +497,13 @@ struct kvm_run { · 220 unmodified lines | |||
| 496 | unsigned long args[6]; | 497 | unsigned long args[6]; |
| 497 | unsigned long ret[2]; | 498 | unsigned long ret[2]; |
| 498 | } riscv_sbi; | 499 | } riscv_sbi; |
| 500 | /* KVM_EXIT_RISCV_CSR */ | ||
| 501 | struct { | ||
| 502 | unsigned long csr_num; | ||
| 503 | unsigned long new_value; | ||
| 504 | unsigned long write_mask; | ||
| 505 | unsigned long ret_value; | ||
| 506 | } riscv_csr; | ||
| 499 | /* Fix the size of the union. */ | 507 | /* Fix the size of the union. */ |
| 500 | char padding[256]; | 508 | char padding[256]; |
| 501 | }; | 509 | }; |