On Fri, Apr 26, 2024 at 06:17:08PM -0700, Deepak Gupta wrote:
On Thu, Apr 18, 2024 at 04:26:45PM +0200, Clément Léger wrote:Add support in KVM SBI FWFT extension to allow VS-mode to request double trap enabling. Double traps can then be generated by VS-mode, allowing M-mode to redirect them to S-mode. Signed-off-by: Clément Léger <cleger@xxxxxxxxxxxx> --- arch/riscv/include/asm/csr.h | 1 + arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h | 2 +- arch/riscv/kvm/vcpu_sbi_fwft.c | 41 ++++++++++++++++++++++ 3 files changed, 43 insertions(+), 1 deletion(-) diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h index 905cdf894a57..ee1b73655bec 100644 --- a/arch/riscv/include/asm/csr.h +++ b/arch/riscv/include/asm/csr.h @@ -196,6 +196,7 @@ /* xENVCFG flags */ #define ENVCFG_STCE (_AC(1, ULL) << 63) #define ENVCFG_PBMTE (_AC(1, ULL) << 62) +#define ENVCFG_DTE (_AC(1, ULL) << 59) #define ENVCFG_CBZE (_AC(1, UL) << 7) #define ENVCFG_CBCFE (_AC(1, UL) << 6) #define ENVCFG_CBIE_SHIFT 4 diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h b/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h index 7dc1b80c7e6c..a9e20d655126 100644 --- a/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h +++ b/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h @@ -11,7 +11,7 @@ #include <asm/sbi.h> -#define KVM_SBI_FWFT_FEATURE_COUNT 1 +#define KVM_SBI_FWFT_FEATURE_COUNT 2 struct kvm_sbi_fwft_config; struct kvm_vcpu; diff --git a/arch/riscv/kvm/vcpu_sbi_fwft.c b/arch/riscv/kvm/vcpu_sbi_fwft.c index b9b7f8fa6d22..9e8e397eb02f 100644 --- a/arch/riscv/kvm/vcpu_sbi_fwft.c +++ b/arch/riscv/kvm/vcpu_sbi_fwft.c @@ -9,10 +9,19 @@ #include <linux/errno.h> #include <linux/err.h> #include <linux/kvm_host.h> +#include <linux/riscv_dbltrp.h> #include <asm/sbi.h> #include <asm/kvm_vcpu_sbi.h> #include <asm/kvm_vcpu_sbi_fwft.h> +#ifdef CONFIG_32BIT +# define CSR_HENVCFG_DBLTRP CSR_HENVCFGH +# define DBLTRP_DTE (ENVCFG_DTE >> 32) +#else +# define CSR_HENVCFG_DBLTRP CSR_HENVCFG +# define DBLTRP_DTE ENVCFG_DTE +#endif + #define MIS_DELEG (1UL << EXC_LOAD_MISALIGNED | 1UL << EXC_STORE_MISALIGNED) static int kvm_sbi_fwft_set_misaligned_delegation(struct kvm_vcpu *vcpu, @@ -36,6 +45,33 @@ static int kvm_sbi_fwft_get_misaligned_delegation(struct kvm_vcpu *vcpu, return SBI_SUCCESS; } +static int kvm_sbi_fwft_set_double_trap(struct kvm_vcpu *vcpu, + struct kvm_sbi_fwft_config *conf, + unsigned long value) +{ + if (!riscv_double_trap_enabled()) + return SBI_ERR_NOT_SUPPORTED;Why its required to check whether host has enabled double trap for itself ? It's orthogonal to guest asking hypervisor to enable double trap. Probably you need a check here whether underlying FW supports handling double trap. Am I missing something here?
On this I am indeed missing that menvcfg.DTE has to be 1 for any less priv. So, nevermind on this comment. Sorry about that.
