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KVM: arm64: Make struct kvm_regs userspace-only

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struct kvm_regs is used by userspace to indicate which register gets
accessed by the {GET,SET}_ONE_REG API. But as we're about to refactor
the layout of the in-kernel register structures, we need the kernel to
move away from it.

Let's make kvm_regs userspace only, and let the kernel map it to its own
internal representation.

Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Marc Zyngier 2019-06-28 22:40:58 +01:00
parent 5b78077a00
commit e47c2055c6
10 changed files with 96 additions and 48 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
arch/arm64/include/asm/kvm_emulate.h
View File

@ -124,12 +124,12 @@ static inline void vcpu_set_vsesr(struct kvm_vcpu *vcpu, u64 vsesr)
static __always_inline unsigned long *vcpu_pc(const struct kvm_vcpu *vcpu)
{
return (unsigned long *)&vcpu_gp_regs(vcpu)->regs.pc;
return (unsigned long *)&vcpu_gp_regs(vcpu)->pc;
}
static inline unsigned long *__vcpu_elr_el1(const struct kvm_vcpu *vcpu)
{
return (unsigned long *)&vcpu_gp_regs(vcpu)->elr_el1;
return (unsigned long *)&vcpu->arch.ctxt.elr_el1;
}
static inline unsigned long vcpu_read_elr_el1(const struct kvm_vcpu *vcpu)
@ -150,7 +150,7 @@ static inline void vcpu_write_elr_el1(const struct kvm_vcpu *vcpu, unsigned long
static __always_inline unsigned long *vcpu_cpsr(const struct kvm_vcpu *vcpu)
{
return (unsigned long *)&vcpu_gp_regs(vcpu)->regs.pstate;
return (unsigned long *)&vcpu_gp_regs(vcpu)->pstate;
}
static __always_inline bool vcpu_mode_is_32bit(const struct kvm_vcpu *vcpu)
@ -179,14 +179,14 @@ static inline void vcpu_set_thumb(struct kvm_vcpu *vcpu)
static __always_inline unsigned long vcpu_get_reg(const struct kvm_vcpu *vcpu,
u8 reg_num)
{
return (reg_num == 31) ? 0 : vcpu_gp_regs(vcpu)->regs.regs[reg_num];
return (reg_num == 31) ? 0 : vcpu_gp_regs(vcpu)->regs[reg_num];
}
static __always_inline void vcpu_set_reg(struct kvm_vcpu *vcpu, u8 reg_num,
unsigned long val)
{
if (reg_num != 31)
vcpu_gp_regs(vcpu)->regs.regs[reg_num] = val;
vcpu_gp_regs(vcpu)->regs[reg_num] = val;
}
static inline unsigned long vcpu_read_spsr(const struct kvm_vcpu *vcpu)
@ -197,7 +197,7 @@ static inline unsigned long vcpu_read_spsr(const struct kvm_vcpu *vcpu)
if (vcpu->arch.sysregs_loaded_on_cpu)
return read_sysreg_el1(SYS_SPSR);
else
return vcpu_gp_regs(vcpu)->spsr[KVM_SPSR_EL1];
return vcpu->arch.ctxt.spsr[KVM_SPSR_EL1];
}
static inline void vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long v)
@ -210,7 +210,7 @@ static inline void vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long v)
if (vcpu->arch.sysregs_loaded_on_cpu)
write_sysreg_el1(v, SYS_SPSR);
else
vcpu_gp_regs(vcpu)->spsr[KVM_SPSR_EL1] = v;
vcpu->arch.ctxt.spsr[KVM_SPSR_EL1] = v;
}
/*
@ -519,11 +519,11 @@ static __always_inline void kvm_skip_instr(struct kvm_vcpu *vcpu, bool is_wide_i
static __always_inline void __kvm_skip_instr(struct kvm_vcpu *vcpu)
{
*vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR);
vcpu->arch.ctxt.gp_regs.regs.pstate = read_sysreg_el2(SYS_SPSR);
vcpu_gp_regs(vcpu)->pstate = read_sysreg_el2(SYS_SPSR);
kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
write_sysreg_el2(vcpu->arch.ctxt.gp_regs.regs.pstate, SYS_SPSR);
write_sysreg_el2(vcpu_gp_regs(vcpu)->pstate, SYS_SPSR);
write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR);
}

12
arch/arm64/include/asm/kvm_host.h
View File

@ -236,7 +236,15 @@ enum vcpu_sysreg {
#define NR_COPRO_REGS (NR_SYS_REGS * 2)
struct kvm_cpu_context {
struct kvm_regs gp_regs;
struct user_pt_regs regs; /* sp = sp_el0 */
u64 sp_el1;
u64 elr_el1;
u64 spsr[KVM_NR_SPSR];
struct user_fpsimd_state fp_regs;
union {
u64 sys_regs[NR_SYS_REGS];
u32 copro[NR_COPRO_REGS];
@ -402,7 +410,7 @@ struct kvm_vcpu_arch {
system_supports_generic_auth()) && \
((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_PTRAUTH))
#define vcpu_gp_regs(v) (&(v)->arch.ctxt.gp_regs)
#define vcpu_gp_regs(v) (&(v)->arch.ctxt.regs)
/*
* Only use __vcpu_sys_reg/ctxt_sys_reg if you know you want the

3
arch/arm64/kernel/asm-offsets.c
View File

@ -102,13 +102,12 @@ int main(void)
DEFINE(VCPU_FAULT_DISR, offsetof(struct kvm_vcpu, arch.fault.disr_el1));
DEFINE(VCPU_WORKAROUND_FLAGS, offsetof(struct kvm_vcpu, arch.workaround_flags));
DEFINE(VCPU_HCR_EL2, offsetof(struct kvm_vcpu, arch.hcr_el2));
DEFINE(CPU_GP_REGS, offsetof(struct kvm_cpu_context, gp_regs));
DEFINE(CPU_USER_PT_REGS, offsetof(struct kvm_cpu_context, regs));
DEFINE(CPU_APIAKEYLO_EL1, offsetof(struct kvm_cpu_context, sys_regs[APIAKEYLO_EL1]));
DEFINE(CPU_APIBKEYLO_EL1, offsetof(struct kvm_cpu_context, sys_regs[APIBKEYLO_EL1]));
DEFINE(CPU_APDAKEYLO_EL1, offsetof(struct kvm_cpu_context, sys_regs[APDAKEYLO_EL1]));
DEFINE(CPU_APDBKEYLO_EL1, offsetof(struct kvm_cpu_context, sys_regs[APDBKEYLO_EL1]));
DEFINE(CPU_APGAKEYLO_EL1, offsetof(struct kvm_cpu_context, sys_regs[APGAKEYLO_EL1]));
DEFINE(CPU_USER_PT_REGS, offsetof(struct kvm_regs, regs));
DEFINE(HOST_CONTEXT_VCPU, offsetof(struct kvm_cpu_context, __hyp_running_vcpu));
DEFINE(HOST_DATA_CONTEXT, offsetof(struct kvm_host_data, host_ctxt));
#endif

2
arch/arm64/kvm/fpsimd.c
View File

@ -85,7 +85,7 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu)
WARN_ON_ONCE(!irqs_disabled());
if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) {
fpsimd_bind_state_to_cpu(&vcpu->arch.ctxt.gp_regs.fp_regs,
fpsimd_bind_state_to_cpu(&vcpu->arch.ctxt.fp_regs,
vcpu->arch.sve_state,
vcpu->arch.sve_max_vl);

70
arch/arm64/kvm/guest.c
View File

@ -101,19 +101,60 @@ static int core_reg_size_from_offset(const struct kvm_vcpu *vcpu, u64 off)
return size;
}
static int validate_core_offset(const struct kvm_vcpu *vcpu,
const struct kvm_one_reg *reg)
static void *core_reg_addr(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
u64 off = core_reg_offset_from_id(reg->id);
int size = core_reg_size_from_offset(vcpu, off);
if (size < 0)
return -EINVAL;
return NULL;
if (KVM_REG_SIZE(reg->id) != size)
return -EINVAL;
return NULL;
return 0;
switch (off) {
case KVM_REG_ARM_CORE_REG(regs.regs[0]) ...
KVM_REG_ARM_CORE_REG(regs.regs[30]):
off -= KVM_REG_ARM_CORE_REG(regs.regs[0]);
off /= 2;
return &vcpu->arch.ctxt.regs.regs[off];
case KVM_REG_ARM_CORE_REG(regs.sp):
return &vcpu->arch.ctxt.regs.sp;
case KVM_REG_ARM_CORE_REG(regs.pc):
return &vcpu->arch.ctxt.regs.pc;
case KVM_REG_ARM_CORE_REG(regs.pstate):
return &vcpu->arch.ctxt.regs.pstate;
case KVM_REG_ARM_CORE_REG(sp_el1):
return &vcpu->arch.ctxt.sp_el1;
case KVM_REG_ARM_CORE_REG(elr_el1):
return &vcpu->arch.ctxt.elr_el1;
case KVM_REG_ARM_CORE_REG(spsr[0]) ...
KVM_REG_ARM_CORE_REG(spsr[KVM_NR_SPSR - 1]):
off -= KVM_REG_ARM_CORE_REG(spsr[0]);
off /= 2;
return &vcpu->arch.ctxt.spsr[off];
case KVM_REG_ARM_CORE_REG(fp_regs.vregs[0]) ...
KVM_REG_ARM_CORE_REG(fp_regs.vregs[31]):
off -= KVM_REG_ARM_CORE_REG(fp_regs.vregs[0]);
off /= 4;
return &vcpu->arch.ctxt.fp_regs.vregs[off];
case KVM_REG_ARM_CORE_REG(fp_regs.fpsr):
return &vcpu->arch.ctxt.fp_regs.fpsr;
case KVM_REG_ARM_CORE_REG(fp_regs.fpcr):
return &vcpu->arch.ctxt.fp_regs.fpcr;
default:
return NULL;
}
}
static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
@ -125,8 +166,8 @@ static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
* off the index in the "array".
*/
__u32 __user *uaddr = (__u32 __user *)(unsigned long)reg->addr;
struct kvm_regs *regs = vcpu_gp_regs(vcpu);
int nr_regs = sizeof(*regs) / sizeof(__u32);
int nr_regs = sizeof(struct kvm_regs) / sizeof(__u32);
void *addr;
u32 off;
/* Our ID is an index into the kvm_regs struct. */
@ -135,10 +176,11 @@ static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
(off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
return -ENOENT;
if (validate_core_offset(vcpu, reg))
addr = core_reg_addr(vcpu, reg);
if (!addr)
return -EINVAL;
if (copy_to_user(uaddr, ((u32 *)regs) + off, KVM_REG_SIZE(reg->id)))
if (copy_to_user(uaddr, addr, KVM_REG_SIZE(reg->id)))
return -EFAULT;
return 0;
@ -147,10 +189,9 @@ static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
__u32 __user *uaddr = (__u32 __user *)(unsigned long)reg->addr;
struct kvm_regs *regs = vcpu_gp_regs(vcpu);
int nr_regs = sizeof(*regs) / sizeof(__u32);
int nr_regs = sizeof(struct kvm_regs) / sizeof(__u32);
__uint128_t tmp;
void *valp = &tmp;
void *valp = &tmp, *addr;
u64 off;
int err = 0;
@ -160,7 +201,8 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
(off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
return -ENOENT;
if (validate_core_offset(vcpu, reg))
addr = core_reg_addr(vcpu, reg);
if (!addr)
return -EINVAL;
if (KVM_REG_SIZE(reg->id) > sizeof(tmp))
@ -198,7 +240,7 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
}
}
memcpy((u32 *)regs + off, valp, KVM_REG_SIZE(reg->id));
memcpy(addr, valp, KVM_REG_SIZE(reg->id));
if (*vcpu_cpsr(vcpu) & PSR_MODE32_BIT) {
int i;

3
arch/arm64/kvm/hyp/entry.S
View File

@ -16,8 +16,7 @@
#include <asm/kvm_mmu.h>
#include <asm/kvm_ptrauth.h>
#define CPU_GP_REG_OFFSET(x) (CPU_GP_REGS + x)
#define CPU_XREG_OFFSET(x) CPU_GP_REG_OFFSET(CPU_USER_PT_REGS + 8*x)
#define CPU_XREG_OFFSET(x) (CPU_USER_PT_REGS + 8*x)
#define CPU_SP_EL0_OFFSET (CPU_XREG_OFFSET(30) + 8)
.text

4
arch/arm64/kvm/hyp/include/hyp/switch.h
View File

@ -266,11 +266,11 @@ static inline bool __hyp_handle_fpsimd(struct kvm_vcpu *vcpu)
if (sve_guest) {
sve_load_state(vcpu_sve_pffr(vcpu),
&vcpu->arch.ctxt.gp_regs.fp_regs.fpsr,
&vcpu->arch.ctxt.fp_regs.fpsr,
sve_vq_from_vl(vcpu->arch.sve_max_vl) - 1);
write_sysreg_s(__vcpu_sys_reg(vcpu, ZCR_EL1), SYS_ZCR_EL12);
} else {
__fpsimd_restore_state(&vcpu->arch.ctxt.gp_regs.fp_regs);
__fpsimd_restore_state(&vcpu->arch.ctxt.fp_regs);
}
/* Skip restoring fpexc32 for AArch64 guests */

24
arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
View File

@ -46,15 +46,15 @@ static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
ctxt_sys_reg(ctxt, PAR_EL1) = read_sysreg(par_el1);
ctxt_sys_reg(ctxt, TPIDR_EL1) = read_sysreg(tpidr_el1);
ctxt->gp_regs.sp_el1 = read_sysreg(sp_el1);
ctxt->gp_regs.elr_el1 = read_sysreg_el1(SYS_ELR);
ctxt->gp_regs.spsr[KVM_SPSR_EL1]= read_sysreg_el1(SYS_SPSR);
ctxt->sp_el1 = read_sysreg(sp_el1);
ctxt->elr_el1 = read_sysreg_el1(SYS_ELR);
ctxt->spsr[KVM_SPSR_EL1] = read_sysreg_el1(SYS_SPSR);
}
static inline void __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt)
{
ctxt->gp_regs.regs.pc = read_sysreg_el2(SYS_ELR);
ctxt->gp_regs.regs.pstate = read_sysreg_el2(SYS_SPSR);
ctxt->regs.pc = read_sysreg_el2(SYS_ELR);
ctxt->regs.pstate = read_sysreg_el2(SYS_SPSR);
if (cpus_have_final_cap(ARM64_HAS_RAS_EXTN))
ctxt_sys_reg(ctxt, DISR_EL1) = read_sysreg_s(SYS_VDISR_EL2);
@ -125,14 +125,14 @@ static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
write_sysreg_el1(ctxt_sys_reg(ctxt, TCR_EL1), SYS_TCR);
}
write_sysreg(ctxt->gp_regs.sp_el1, sp_el1);
write_sysreg_el1(ctxt->gp_regs.elr_el1, SYS_ELR);
write_sysreg_el1(ctxt->gp_regs.spsr[KVM_SPSR_EL1],SYS_SPSR);
write_sysreg(ctxt->sp_el1, sp_el1);
write_sysreg_el1(ctxt->elr_el1, SYS_ELR);
write_sysreg_el1(ctxt->spsr[KVM_SPSR_EL1], SYS_SPSR);
}
static inline void __sysreg_restore_el2_return_state(struct kvm_cpu_context *ctxt)
{
u64 pstate = ctxt->gp_regs.regs.pstate;
u64 pstate = ctxt->regs.pstate;
u64 mode = pstate & PSR_AA32_MODE_MASK;
/*
@ -149,7 +149,7 @@ static inline void __sysreg_restore_el2_return_state(struct kvm_cpu_context *ctx
if (!(mode & PSR_MODE32_BIT) && mode >= PSR_MODE_EL2t)
pstate = PSR_MODE_EL2h | PSR_IL_BIT;
write_sysreg_el2(ctxt->gp_regs.regs.pc, SYS_ELR);
write_sysreg_el2(ctxt->regs.pc, SYS_ELR);
write_sysreg_el2(pstate, SYS_SPSR);
if (cpus_have_final_cap(ARM64_HAS_RAS_EXTN))
@ -163,7 +163,7 @@ static inline void __sysreg32_save_state(struct kvm_vcpu *vcpu)
if (!vcpu_el1_is_32bit(vcpu))
return;
spsr = vcpu->arch.ctxt.gp_regs.spsr;
spsr = vcpu->arch.ctxt.spsr;
spsr[KVM_SPSR_ABT] = read_sysreg(spsr_abt);
spsr[KVM_SPSR_UND] = read_sysreg(spsr_und);
@ -184,7 +184,7 @@ static inline void __sysreg32_restore_state(struct kvm_vcpu *vcpu)
if (!vcpu_el1_is_32bit(vcpu))
return;
spsr = vcpu->arch.ctxt.gp_regs.spsr;
spsr = vcpu->arch.ctxt.spsr;
write_sysreg(spsr[KVM_SPSR_ABT], spsr_abt);
write_sysreg(spsr[KVM_SPSR_UND], spsr_und);

6
arch/arm64/kvm/regmap.c
View File

@ -100,7 +100,7 @@ static const unsigned long vcpu_reg_offsets[VCPU_NR_MODES][16] = {
*/
unsigned long *vcpu_reg32(const struct kvm_vcpu *vcpu, u8 reg_num)
{
unsigned long *reg_array = (unsigned long *)&vcpu->arch.ctxt.gp_regs.regs;
unsigned long *reg_array = (unsigned long *)&vcpu->arch.ctxt.regs;
unsigned long mode = *vcpu_cpsr(vcpu) & PSR_AA32_MODE_MASK;
switch (mode) {
@ -148,7 +148,7 @@ unsigned long vcpu_read_spsr32(const struct kvm_vcpu *vcpu)
int spsr_idx = vcpu_spsr32_mode(vcpu);
if (!vcpu->arch.sysregs_loaded_on_cpu)
return vcpu_gp_regs(vcpu)->spsr[spsr_idx];
return vcpu->arch.ctxt.spsr[spsr_idx];
switch (spsr_idx) {
case KVM_SPSR_SVC:
@ -171,7 +171,7 @@ void vcpu_write_spsr32(struct kvm_vcpu *vcpu, unsigned long v)
int spsr_idx = vcpu_spsr32_mode(vcpu);
if (!vcpu->arch.sysregs_loaded_on_cpu) {
vcpu_gp_regs(vcpu)->spsr[spsr_idx] = v;
vcpu->arch.ctxt.spsr[spsr_idx] = v;
return;
}

2
arch/arm64/kvm/reset.c
View File

@ -288,7 +288,7 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
/* Reset core registers */
memset(vcpu_gp_regs(vcpu), 0, sizeof(*vcpu_gp_regs(vcpu)));
vcpu_gp_regs(vcpu)->regs.pstate = pstate;
vcpu_gp_regs(vcpu)->pstate = pstate;
/* Reset system registers */
kvm_reset_sys_regs(vcpu);