From: Charlie Jenkins <[email protected]> To test the riscv kvm implementation of emulated CSRs, add support to emulate the vsscratch csr when CONFIG_RISCV_KVM_TEST_CSR is set.
Signed-off-by: Charlie Jenkins <[email protected]> --- arch/riscv/Kconfig.debug | 1 + arch/riscv/include/asm/kvm_host.h | 10 ++++++++++ arch/riscv/include/asm/kvm_vcpu_test_csr.h | 15 +++++++++++++++ arch/riscv/kvm/Kconfig.debug | 16 ++++++++++++++++ arch/riscv/kvm/Makefile | 1 + arch/riscv/kvm/vcpu_insn.c | 5 +++++ arch/riscv/kvm/vcpu_test_csr.c | 21 +++++++++++++++++++++ 7 files changed, 69 insertions(+) diff --git a/arch/riscv/Kconfig.debug b/arch/riscv/Kconfig.debug index eafe17ebf710..be202267da6d 100644 --- a/arch/riscv/Kconfig.debug +++ b/arch/riscv/Kconfig.debug @@ -1 +1,2 @@ source "arch/riscv/kernel/tests/Kconfig.debug" +source "arch/riscv/kvm/Kconfig.debug" diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h index 24585304c02b..709a1c18ce22 100644 --- a/arch/riscv/include/asm/kvm_host.h +++ b/arch/riscv/include/asm/kvm_host.h @@ -183,6 +183,12 @@ struct kvm_vcpu_reset_state { unsigned long a1; }; +#ifdef CONFIG_RISCV_KVM_TEST_CSR +struct kvm_test_csr { + unsigned long val; +}; +#endif + struct kvm_vcpu_arch { /* VCPU ran at least once */ bool ran_atleast_once; @@ -278,6 +284,10 @@ struct kvm_vcpu_arch { gpa_t shmem; u64 last_steal; } sta; + +#ifdef CONFIG_RISCV_KVM_TEST_CSR + struct kvm_test_csr test_csr; +#endif }; /* diff --git a/arch/riscv/include/asm/kvm_vcpu_test_csr.h b/arch/riscv/include/asm/kvm_vcpu_test_csr.h new file mode 100644 index 000000000000..a844fccaafc3 --- /dev/null +++ b/arch/riscv/include/asm/kvm_vcpu_test_csr.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef __KVM_VCPU_RISCV_TEST_CSR_H +#define __KVM_VCPU_RISCV_TEST_CSR_H + +#include <asm/kvm_vcpu_insn.h> + +#define KVM_RISCV_VCPU_TEST_CSR_FUNCS \ + {.base = CSR_VSSCRATCH, .count = 1, .func = kvm_riscv_vcpu_test_csr }, + +int kvm_riscv_vcpu_test_csr(struct kvm_vcpu *vcpu, unsigned int csr_num, + unsigned long *val, unsigned long new_val, + unsigned long wr_mask); + +#endif /* !__KVM_VCPU_RISCV_TEST_CSR_H */ diff --git a/arch/riscv/kvm/Kconfig.debug b/arch/riscv/kvm/Kconfig.debug new file mode 100644 index 000000000000..dc76e02120a3 --- /dev/null +++ b/arch/riscv/kvm/Kconfig.debug @@ -0,0 +1,16 @@ +# SPDX-License-Identifier: GPL-2.0-only +menu "arch/riscv/kvm testing" + +config RISCV_KVM_TEST_CSR + bool "Test KVM CSR emulation" + depends on KVM + default n + help + Enable this option to enable the emulation of a test hypervisor csr. + The KVM test csr is the vsscratch register. Once this is enabled, + reading/writing to the vsscratch register will trap into the host + supervisor and reflect the change. + + If unsure, say N. + +endmenu # "arch/riscv/kvm testing" diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile index 3b8afb038b35..02fd27ff33eb 100644 --- a/arch/riscv/kvm/Makefile +++ b/arch/riscv/kvm/Makefile @@ -36,6 +36,7 @@ kvm-y += vcpu_sbi_sta.o kvm-y += vcpu_sbi_system.o kvm-$(CONFIG_RISCV_SBI_V01) += vcpu_sbi_v01.o kvm-y += vcpu_switch.o +kvm-$(CONFIG_RISCV_KVM_TEST_CSR) += vcpu_test_csr.o kvm-y += vcpu_timer.o kvm-y += vcpu_vector.o kvm-y += vm.o diff --git a/arch/riscv/kvm/vcpu_insn.c b/arch/riscv/kvm/vcpu_insn.c index 1d8741d02242..c5a70de4a579 100644 --- a/arch/riscv/kvm/vcpu_insn.c +++ b/arch/riscv/kvm/vcpu_insn.c @@ -10,6 +10,8 @@ #include <asm/cpufeature.h> #include <asm/insn.h> +#include <asm/kvm_vcpu_test_csr.h> + struct insn_func { unsigned long mask; unsigned long match; @@ -112,6 +114,9 @@ static int seed_csr_rmw(struct kvm_vcpu *vcpu, unsigned int csr_num, static const struct csr_func csr_funcs[] = { KVM_RISCV_VCPU_AIA_CSR_FUNCS KVM_RISCV_VCPU_HPMCOUNTER_CSR_FUNCS +#ifdef CONFIG_RISCV_KVM_TEST_CSR + KVM_RISCV_VCPU_TEST_CSR_FUNCS +#endif { .base = CSR_SEED, .count = 1, .func = seed_csr_rmw }, }; diff --git a/arch/riscv/kvm/vcpu_test_csr.c b/arch/riscv/kvm/vcpu_test_csr.c new file mode 100644 index 000000000000..b8aa503cdaba --- /dev/null +++ b/arch/riscv/kvm/vcpu_test_csr.c @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/kvm_host.h> +#include <asm/kvm_vcpu_insn.h> +#include <asm/kvm_vcpu_test_csr.h> + +#define vcpu_to_test_csr(vcpu) (&(vcpu)->arch.test_csr) + +int kvm_riscv_vcpu_test_csr(struct kvm_vcpu *vcpu, unsigned int csr_num, + unsigned long *val, unsigned long new_val, + unsigned long wr_mask) +{ + struct kvm_test_csr *test_csr = vcpu_to_test_csr(vcpu); + + *val = test_csr->val; + + if (wr_mask) + test_csr->val = (test_csr->val & ~wr_mask) | (new_val & wr_mask); + + return KVM_INSN_CONTINUE_NEXT_SEPC; +} -- 2.52.0
