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path: root/arch/riscv/kvm/vcpu_exit.c
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2024-12-30RISC-V: KVM: Add new exit statstics for redirected trapsAtish Patra
Currently, kvm doesn't delegate the few traps such as misaligned load/store, illegal instruction and load/store access faults because it is not expected to occur in the guest very frequently. Thus, kvm gets a chance to act upon it or collect statistics about it before redirecting the traps to the guest. Collect both guest and host visible statistics during the traps. Enable them so that both guest and host can collect the stats about them if required. Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20241224-kvm_guest_stat-v2-3-08a77ac36b02@rivosinc.com Signed-off-by: Anup Patel <anup@brainfault.org>
2024-12-30RISC-V: KVM: Update firmware counters for various eventsAtish Patra
SBI PMU specification defines few firmware counters which can be used by the guests to collect the statstics about various traps occurred in the host. Update these counters whenever a corresponding trap is taken Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20241224-kvm_guest_stat-v2-2-08a77ac36b02@rivosinc.com Signed-off-by: Anup Patel <anup@brainfault.org>
2024-12-30RISC-V: KVM: Redirect instruction access fault trap to guestQuan Zhou
The M-mode redirects an unhandled instruction access fault trap back to S-mode when not delegating it to VS-mode(hedeleg). However, KVM running in HS-mode terminates the VS-mode software when back from M-mode. The KVM should redirect the trap back to VS-mode, and let VS-mode trap handler decide the next step. Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20241224-kvm_guest_stat-v2-1-08a77ac36b02@rivosinc.com Signed-off-by: Anup Patel <anup@brainfault.org>
2024-06-26RISC-V: KVM: Redirect AMO load/store access fault traps to guestYu-Wei Hsu
The KVM RISC-V does not delegate AMO load/store access fault traps to VS-mode (hedeleg) so typically M-mode takes these traps and redirects them back to HS-mode. However, upon returning from M-mode, the KVM RISC-V running in HS-mode terminates VS-mode software. The KVM RISC-V should redirect AMO load/store access fault traps back to VS-mode and let the VS-mode trap handler determine the next steps. Signed-off-by: Yu-Wei Hsu <betterman5240@gmail.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20240429092113.70695-1-betterman5240@gmail.com Signed-off-by: Anup Patel <anup@brainfault.org>
2024-04-08RISC-V: KVM: Handle breakpoint exits for VCPUChao Du
Exit to userspace for breakpoint traps. Set the exit_reason as KVM_EXIT_DEBUG before exit. Signed-off-by: Chao Du <duchao@eswincomputing.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20240402062628.5425-3-duchao@eswincomputing.com Signed-off-by: Anup Patel <anup@brainfault.org>
2023-06-06RISC-V: KVM: Redirect AMO load/store misaligned traps to guestwchen
The M-mode redirects an unhandled misaligned trap back to S-mode when not delegating it to VS-mode(hedeleg). However, KVM running in HS-mode terminates the VS-mode software when back from M-mode. The KVM should redirect the trap back to VS-mode, and let VS-mode trap handler decide the next step. Here is a way to handle misaligned traps in KVM, not only directing them to VS-mode or terminate it. Signed-off-by: wchen <waylingII@gmail.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Anup Patel <anup@brainfault.org>
2023-02-07RISC-V: KVM: Redirect illegal instruction traps to guestAndy Chiu
The M-mode redirects an unhandled illegal instruction trap back to S-mode. However, KVM running in HS-mode terminates the VS-mode software when it receives illegal instruction trap. Instead, KVM should redirect the illegal instruction trap back to VS-mode, and let VS-mode trap handler decide the next step. This futher allows guest kernel to implement on-demand enabling of vector extension for a guest user space process upon first-use. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2023-02-07RISC-V: KVM: Fix privilege mode setting in kvm_riscv_vcpu_trap_redirect()Anup Patel
The kvm_riscv_vcpu_trap_redirect() should set guest privilege mode to supervisor mode because guest traps/interrupts are always handled in virtual supervisor mode. Fixes: 9f7013265112 ("RISC-V: KVM: Handle MMIO exits for VCPU") Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-10-02riscv: KVM: Apply insn-def to hlv encodingsAndrew Jones
Introduce hlv instruction encodings and apply them to KVM's use. We're careful not to introduce hlv.d to 32-bit builds. Indeed, we ensure the build fails if someone tries to use it. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-29RISC-V: KVM: Factor-out instruction emulation into separate sourcesAnup Patel
The instruction and CSR emulation for VCPU is going to grow over time due to upcoming AIA, PMU, Nested and other virtualization features. Let us factor-out VCPU instruction emulation from vcpu_exit.c to a separate source dedicated for this purpose. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-29RISC-V: KVM: Fix variable spelling mistakeZhang Jiaming
There is a spelling mistake in mmu.c and vcpu_exit.c. Fix it. Signed-off-by: Zhang Jiaming <jiaming@nfschina.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20RISC-V: KVM: Use G-stage name for hypervisor page tableAnup Patel
The two-stage address translation defined by the RISC-V privileged specification defines: VS-stage (guest virtual address to guest physical address) programmed by the Guest OS and G-stage (guest physical addree to host physical address) programmed by the hypervisor. To align with above terminology, we replace "stage2" with "gstage" and "Stage2" with "G-stage" name everywhere in KVM RISC-V sources. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-04-21KVM: Add helpers to wrap vcpu->srcu_idx and yell if it's abusedSean Christopherson
Add wrappers to acquire/release KVM's SRCU lock when stashing the index in vcpu->src_idx, along with rudimentary detection of illegal usage, e.g. re-acquiring SRCU and thus overwriting vcpu->src_idx. Because the SRCU index is (currently) either 0 or 1, illegal nesting bugs can go unnoticed for quite some time and only cause problems when the nested lock happens to get a different index. Wrap the WARNs in PROVE_RCU=y, and make them ONCE, otherwise KVM will likely yell so loudly that it will bring the kernel to its knees. Signed-off-by: Sean Christopherson <seanjc@google.com> Tested-by: Fabiano Rosas <farosas@linux.ibm.com> Message-Id: <20220415004343.2203171-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-21KVM: RISC-V: Use kvm_vcpu.srcu_idx, drop RISC-V's unnecessary copySean Christopherson
Use the generic kvm_vcpu's srcu_idx instead of using an indentical field in RISC-V's version of kvm_vcpu_arch. Generic KVM very intentionally does not touch vcpu->srcu_idx, i.e. there's zero chance of running afoul of common code. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220415004343.2203171-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-11RISC-V: KVM: Add common kvm_riscv_vcpu_wfi() functionAnup Patel
The wait for interrupt (WFI) instruction emulation can share the VCPU halt logic with SBI HSM suspend emulation so this patch adds a common kvm_riscv_vcpu_wfi() function for this purpose. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2021-12-08KVM: Rename kvm_vcpu_block() => kvm_vcpu_halt()Sean Christopherson
Rename kvm_vcpu_block() to kvm_vcpu_halt() in preparation for splitting the actual "block" sequences into a separate helper (to be named kvm_vcpu_block()). x86 will use the standalone block-only path to handle non-halt cases where the vCPU is not runnable. Rename block_ns to halt_ns to match the new function name. No functional change intended. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211009021236.4122790-14-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-01RISC-V: KVM: remove unneeded semicolonran jianping
Elimate the following coccinelle check warning: ./arch/riscv/kvm/vcpu_sbi.c:169:2-3: Unneeded semicolon ./arch/riscv/kvm/vcpu_exit.c:397:2-3: Unneeded semicolon ./arch/riscv/kvm/vcpu_exit.c:687:2-3: Unneeded semicolon ./arch/riscv/kvm/vcpu_exit.c:645:2-3: Unneeded semicolon ./arch/riscv/kvm/vcpu.c:247:2-3: Unneeded semicolon ./arch/riscv/kvm/vcpu.c:284:2-3: Unneeded semicolon ./arch/riscv/kvm/vcpu_timer.c:123:2-3: Unneeded semicolon ./arch/riscv/kvm/vcpu_timer.c:170:2-3: Unneeded semicolon Reported-by: Zeal Robot <zealci@zte.com.cn> Signed-off-by: ran jianping <ran.jianping@zte.com.cn> Signed-off-by: Anup Patel <anup.patel@wdc.com>
2021-10-04RISC-V: KVM: Add SBI v0.1 supportAtish Patra
The KVM host kernel is running in HS-mode needs so we need to handle the SBI calls coming from guest kernel running in VS-mode. This patch adds SBI v0.1 support in KVM RISC-V. Almost all SBI v0.1 calls are implemented in KVM kernel module except GETCHAR and PUTCHART calls which are forwarded to user space because these calls cannot be implemented in kernel space. In future, when we implement SBI v0.2 for Guest, we will forward SBI v0.2 experimental and vendor extension calls to user space. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: Handle WFI exits for VCPUAnup Patel
We get illegal instruction trap whenever Guest/VM executes WFI instruction. This patch handles WFI trap by blocking the trapped VCPU using kvm_vcpu_block() API. The blocked VCPU will be automatically resumed whenever a VCPU interrupt is injected from user-space or from in-kernel IRQCHIP emulation. Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: KVM: Handle MMIO exits for VCPUAnup Patel
We will get stage2 page faults whenever Guest/VM access SW emulated MMIO device or unmapped Guest RAM. This patch implements MMIO read/write emulation by extracting MMIO details from the trapped load/store instruction and forwarding the MMIO read/write to user-space. The actual MMIO emulation will happen in user-space and KVM kernel module will only take care of register updates before resuming the trapped VCPU. The handling for stage2 page faults for unmapped Guest RAM will be implemeted by a separate patch later. [jiangyifei: ioeventfd and in-kernel mmio device support] Signed-off-by: Yifei Jiang <jiangyifei@huawei.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Alexander Graf <graf@amazon.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04RISC-V: Add initial skeletal KVM supportAnup Patel
This patch adds initial skeletal KVM RISC-V support which has: 1. A simple implementation of arch specific VM functions except kvm_vm_ioctl_get_dirty_log() which will implemeted in-future as part of stage2 page loging. 2. Stubs of required arch specific VCPU functions except kvm_arch_vcpu_ioctl_run() which is semi-complete and extended by subsequent patches. 3. Stubs for required arch specific stage2 MMU functions. Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Alexander Graf <graf@amazon.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>