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X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org ping? On Thu, 27 Aug 2026, Davidlohr Bueso wrote: >senvcfg arrived in privileged spec 1.12, but H-capable cores on a >1.11 base exist, ie: sifive P500 (ESWIN EIC7700X) implements the >hypervisor extension yet has no senvcfg. KVM swaps the CSR >unconditionally on every vCPU entry, panicing the host upon a guest >executing its first instruction: > > Oops - illegal instruction [#1] > Modules linked in: kvm > CPU: 2 UID: 0 PID: 127 Comm: qemu-system-ris Not tainted 7.2.0-kvm73bug+ #4 PREEMPTLAZY > Hardware name: Unknown Unknown Product/Unknown Product, BIOS 2024.01 01/01/2024 > epc : kvm_riscv_vcpu_enter_exit+0x26/0xcf8 [kvm] > ra : kvm_arch_vcpu_ioctl_run+0x4ce/0x5a6 [kvm] > status: 0000000200000100 badaddr: 0000000010a797f3 cause: 0000000000000002 > [] kvm_riscv_vcpu_enter_exit+0x26/0xcf8 [kvm] > [] kvm_arch_vcpu_ioctl_run+0x4ce/0x5a6 [kvm] > [] kvm_vcpu_ioctl+0x180/0x5e4 [kvm] > [] __riscv_sys_ioctl+0x84/0x9a > [] do_trap_ecall_u+0x1d8/0x38a > [] handle_exception+0x168/0x174 > Code: 84aa 892e b703 8887 1773 1067 3023 16e5 b783 8907 (97f3) 10a7 > >Touch the CSR only when RISCV_ISA_EXT_XLINUXENVCFG is set, similar >to __switch_to_envcfg() as well as other swaps conditional on >their extentions. > >Fixes: db3c01c7a308 ("RISCV: KVM: Add senvcfg context save/restore") >Signed-off-by: Davidlohr Bueso >--- > arch/riscv/kvm/vcpu.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > >diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c >index e062ca19f9d8..0c2d58db13ab 100644 >--- a/arch/riscv/kvm/vcpu.c >+++ b/arch/riscv/kvm/vcpu.c >@@ -773,7 +773,8 @@ static __always_inline void kvm_riscv_vcpu_swap_in_guest_state(struct kvm_vcpu * > struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; > > vcpu->arch.host_scounteren = csr_swap(CSR_SCOUNTEREN, csr->scounteren); >- vcpu->arch.host_senvcfg = csr_swap(CSR_SENVCFG, csr->senvcfg); >+ if (riscv_has_extension_unlikely(RISCV_ISA_EXT_XLINUXENVCFG)) >+ vcpu->arch.host_senvcfg = csr_swap(CSR_SENVCFG, csr->senvcfg); > if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SMSTATEEN)) > vcpu->arch.host_sstateen0 = csr_swap(CSR_SSTATEEN0, smcsr->sstateen0); > if (riscv_has_extension_unlikely(RISCV_ISA_EXT_ZICFISS)) >@@ -787,7 +788,8 @@ static __always_inline void kvm_riscv_vcpu_swap_in_host_state(struct kvm_vcpu *v > struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; > > csr->scounteren = csr_swap(CSR_SCOUNTEREN, vcpu->arch.host_scounteren); >- csr->senvcfg = csr_swap(CSR_SENVCFG, vcpu->arch.host_senvcfg); >+ if (riscv_has_extension_unlikely(RISCV_ISA_EXT_XLINUXENVCFG)) >+ csr->senvcfg = csr_swap(CSR_SENVCFG, vcpu->arch.host_senvcfg); > if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SMSTATEEN)) > smcsr->sstateen0 = csr_swap(CSR_SSTATEEN0, vcpu->arch.host_sstateen0); > if (riscv_has_extension_unlikely(RISCV_ISA_EXT_ZICFISS)) >-- >2.39.5 > > >-- >kvm-riscv mailing list >kvm-riscv@lists.infradead.org >http://lists.infradead.org/mailman/listinfo/kvm-riscv _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv