To support the virtual EL2 execution, we need to maintain the EL2 special registers such as SPSR_EL2, ELR_EL2 and SP_EL2 in vcpu context.
Note that SP_EL2 is not accessible in EL2, so we don't need a trap handler for this register. Signed-off-by: Jintack Lim <jintack....@linaro.org> --- arch/arm64/include/asm/kvm_host.h | 12 ++++++++++++ arch/arm64/include/asm/sysreg.h | 4 ++++ arch/arm64/kvm/sys_regs.c | 38 +++++++++++++++++++++++++++++++++----- arch/arm64/kvm/sys_regs.h | 8 ++++++++ 4 files changed, 57 insertions(+), 5 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 1dc4ed6..57dccde 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -171,6 +171,15 @@ enum vcpu_sysreg { NR_SYS_REGS /* Nothing after this line! */ }; +enum el2_special_regs { + __INVALID_EL2_SPECIAL_REG__, + SPSR_EL2, /* Saved Program Status Register (EL2) */ + ELR_EL2, /* Exception Link Register (EL2) */ + SP_EL2, /* Stack Pointer (EL2) */ + + NR_EL2_SPECIAL_REGS +}; + /* 32bit mapping */ #define c0_MPIDR (MPIDR_EL1 * 2) /* MultiProcessor ID Register */ #define c0_CSSELR (CSSELR_EL1 * 2)/* Cache Size Selection Register */ @@ -218,6 +227,8 @@ struct kvm_cpu_context { u64 sys_regs[NR_SYS_REGS]; u32 copro[NR_COPRO_REGS]; }; + + u64 el2_special_regs[NR_EL2_SPECIAL_REGS]; }; typedef struct kvm_cpu_context kvm_cpu_context_t; @@ -307,6 +318,7 @@ struct kvm_vcpu_arch { #define vcpu_gp_regs(v) (&(v)->arch.ctxt.gp_regs) #define vcpu_sys_reg(v,r) ((v)->arch.ctxt.sys_regs[(r)]) +#define vcpu_el2_sreg(v,r) ((v)->arch.ctxt.el2_special_regs[(r)]) /* * CP14 and CP15 live in the same array, as they are backed by the * same system registers. diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 9277c4a..98c32ef 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -268,6 +268,8 @@ #define SYS_DACR32_EL2 sys_reg(3, 4, 3, 0, 0) +#define SYS_SPSR_EL2 sys_reg(3, 4, 4, 0, 0) +#define SYS_ELR_EL2 sys_reg(3, 4, 4, 0, 1) #define SYS_SP_EL1 sys_reg(3, 4, 4, 1, 0) #define SYS_IFSR32_EL2 sys_reg(3, 4, 5, 0, 1) @@ -332,6 +334,8 @@ #define SYS_CNTVOFF_EL2 sys_reg(3, 4, 14, 0, 3) #define SYS_CNTHCTL_EL2 sys_reg(3, 4, 14, 1, 0) +#define SYS_SP_EL2 sys_reg(3, 6, 4, 1, 0) + /* Common SCTLR_ELx flags. */ #define SCTLR_ELx_EE (1 << 25) #define SCTLR_ELx_I (1 << 12) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 1568f8b..2b3ed70 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -900,15 +900,33 @@ static inline void access_rw(struct sys_reg_params *p, u64 *sysreg) *sysreg = p->regval; } +static u64 *get_special_reg(struct kvm_vcpu *vcpu, struct sys_reg_params *p) +{ + u64 reg = sys_reg(p->Op0, p->Op1, p->CRn, p->CRm, p->Op2); + + switch (reg) { + case SYS_SP_EL1: + return &vcpu->arch.ctxt.gp_regs.sp_el1; + case SYS_ELR_EL2: + return &vcpu_el2_sreg(vcpu, ELR_EL2); + case SYS_SPSR_EL2: + return &vcpu_el2_sreg(vcpu, SPSR_EL2); + default: + return NULL; + }; +} + static bool trap_el2_regs(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { - /* SP_EL1 is NOT maintained in sys_regs array */ - if (sys_reg(p->Op0, p->Op1, p->CRn, p->CRm, p->Op2) == SYS_SP_EL1) - access_rw(p, &vcpu->arch.ctxt.gp_regs.sp_el1); - else - access_rw(p, &vcpu_sys_reg(vcpu, r->reg)); + u64 *sys_reg; + + sys_reg = get_special_reg(vcpu, p); + if (!sys_reg) + sys_reg = &vcpu_sys_reg(vcpu, r->reg); + + access_rw(p, sys_reg); return true; } @@ -1116,6 +1134,8 @@ static bool trap_el2_regs(struct kvm_vcpu *vcpu, { SYS_DESC(SYS_DACR32_EL2), NULL, reset_unknown, DACR32_EL2 }, + { SYS_DESC(SYS_SPSR_EL2), trap_el2_regs, reset_special, SPSR_EL2, 0 }, + { SYS_DESC(SYS_ELR_EL2), trap_el2_regs, reset_special, ELR_EL2, 0 }, { SYS_DESC(SYS_SP_EL1), trap_el2_regs }, { SYS_DESC(SYS_IFSR32_EL2), NULL, reset_unknown, IFSR32_EL2 }, @@ -1138,6 +1158,8 @@ static bool trap_el2_regs(struct kvm_vcpu *vcpu, { SYS_DESC(SYS_CNTVOFF_EL2), trap_el2_regs, reset_val, CNTVOFF_EL2, 0 }, { SYS_DESC(SYS_CNTHCTL_EL2), trap_el2_regs, reset_val, CNTHCTL_EL2, 0 }, + + { SYS_DESC(SYS_SP_EL2), NULL, reset_special, SP_EL2, 0}, }; static bool trap_dbgidr(struct kvm_vcpu *vcpu, @@ -2271,6 +2293,8 @@ void kvm_reset_sys_regs(struct kvm_vcpu *vcpu) /* Catch someone adding a register without putting in reset entry. */ memset(&vcpu->arch.ctxt.sys_regs, 0x42, sizeof(vcpu->arch.ctxt.sys_regs)); + memset(&vcpu->arch.ctxt.el2_special_regs, 0x42, + sizeof(vcpu->arch.ctxt.el2_special_regs)); /* Generic chip reset first (so target could override). */ reset_sys_reg_descs(vcpu, sys_reg_descs, ARRAY_SIZE(sys_reg_descs)); @@ -2281,4 +2305,8 @@ void kvm_reset_sys_regs(struct kvm_vcpu *vcpu) for (num = 1; num < NR_SYS_REGS; num++) if (vcpu_sys_reg(vcpu, num) == 0x4242424242424242) panic("Didn't reset vcpu_sys_reg(%zi)", num); + + for (num = 1; num < NR_EL2_SPECIAL_REGS; num++) + if (vcpu_el2_sreg(vcpu, num) == 0x4242424242424242) + panic("Didn't reset vcpu_el2_sreg(%zi)", num); } diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h index 060f534..827717b 100644 --- a/arch/arm64/kvm/sys_regs.h +++ b/arch/arm64/kvm/sys_regs.h @@ -99,6 +99,14 @@ static inline void reset_val(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r vcpu_sys_reg(vcpu, r->reg) = r->val; } +static inline void reset_special(struct kvm_vcpu *vcpu, + const struct sys_reg_desc *r) +{ + BUG_ON(!r->reg); + BUG_ON(r->reg >= NR_EL2_SPECIAL_REGS); + vcpu_el2_sreg(vcpu, r->reg) = r->val; +} + static inline int cmp_sys_reg(const struct sys_reg_desc *i1, const struct sys_reg_desc *i2) { -- 1.9.1