[PATCH 11/12] KVM: arm64: Unify UNDEF injection helpers

Marc Zyngier
2024-08-20T10:06:20Z

We currently have two helpers (undef_access() and trap_undef()) that
do exactly the same thing: inject an UNDEF and return 'false' (as an
indication that PC should not be incremented).

We definitely could do with one less. Given that undef_access() is
used 80ish times, while trap_undef() is only used 30 times, the
latter loses the battle and is immediately sacrificed.

We also have a large number of instances where undef_access() is
open-coded. Let's also convert those.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/sys_regs.c | 132 +++++++++++++++-----------------------
1 file changed, 51 insertions(+), 81 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index ba6075973a36..0976df0008cc 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -61,8 +61,7 @@ static bool bad_trap(struct kvm_vcpu *vcpu,
{
WARN_ONCE(1, "Unexpected %s\n", msg);
print_sys_reg_instr(params);
- kvm_inject_undefined(vcpu);
- return false;
+ return undef_access(vcpu, params, r);
}

static bool read_from_write_only(struct kvm_vcpu *vcpu,
@@ -353,10 +352,8 @@ static bool access_dcgsw(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
- if (!kvm_has_mte(vcpu->kvm)) {
- kvm_inject_undefined(vcpu);
- return false;
- }
+ if (!kvm_has_mte(vcpu->kvm))
+ return undef_access(vcpu, p, r);

/* Treat MTE S/W ops as we treat the classic ones: with contempt */
return access_dcsw(vcpu, p, r);
@@ -393,10 +390,8 @@ static bool access_vm_reg(struct kvm_vcpu *vcpu,
u64 val, mask, shift;

if (reg_to_encoding(r) == SYS_TCR2_EL1 &&
- !kvm_has_feat(vcpu->kvm, ID_AA64MMFR3_EL1, TCRX, IMP)) {
- kvm_inject_undefined(vcpu);
- return false;
- }
+ !kvm_has_feat(vcpu->kvm, ID_AA64MMFR3_EL1, TCRX, IMP))
+ return undef_access(vcpu, p, r);

BUG_ON(!p->is_write);

@@ -443,10 +438,8 @@ static bool access_gic_sgi(struct kvm_vcpu *vcpu,
{
bool g1;

- if (!kvm_has_gicv3(vcpu->kvm)) {
- kvm_inject_undefined(vcpu);
- return false;
- }
+ if (!kvm_has_gicv3(vcpu->kvm))
+ return undef_access(vcpu, p, r);

if (!p->is_write)
return read_from_write_only(vcpu, p, r);
@@ -511,14 +504,6 @@ static bool trap_raz_wi(struct kvm_vcpu *vcpu,
return read_zero(vcpu, p);
}

-static bool trap_undef(struct kvm_vcpu *vcpu,
- struct sys_reg_params *p,
- const struct sys_reg_desc *r)
-{
- kvm_inject_undefined(vcpu);
- return false;
-}
-
/*
* ARMv8.1 mandates at least a trivial LORegion implementation, where all the
* RW registers are RES0 (which we can implement as RAZ/WI). On an ARMv8.0
@@ -531,10 +516,8 @@ static bool trap_loregion(struct kvm_vcpu *vcpu,
{
u32 sr = reg_to_encoding(r);

- if (!kvm_has_feat(vcpu->kvm, ID_AA64MMFR1_EL1, LO, IMP)) {
- kvm_inject_undefined(vcpu);
- return false;
- }
+ if (!kvm_has_feat(vcpu->kvm, ID_AA64MMFR1_EL1, LO, IMP))
+ return undef_access(vcpu, p, r);

if (p->is_write && sr == SYS_LORID_EL1)
return write_to_read_only(vcpu, p, r);
@@ -1267,10 +1250,8 @@ static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (p->is_write) {
- if (!vcpu_mode_priv(vcpu)) {
- kvm_inject_undefined(vcpu);
- return false;
- }
+ if (!vcpu_mode_priv(vcpu))
+ return undef_access(vcpu, p, r);

__vcpu_sys_reg(vcpu, PMUSERENR_EL0) =
p->regval & ARMV8_PMU_USERENR_MASK;
@@ -1412,8 +1393,7 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu,
break;
default:
print_sys_reg_msg(p, "%s", "Unhandled trapped timer register");
- kvm_inject_undefined(vcpu);
- return false;
+ return undef_access(vcpu, p, r);
}

if (p->is_write)
@@ -2309,7 +2289,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
// DBGDTR[TR]X_EL0 share the same encoding
{ SYS_DESC(SYS_DBGDTRTX_EL0), trap_raz_wi },

- { SYS_DESC(SYS_DBGVCR32_EL2), trap_undef, reset_val, DBGVCR32_EL2, 0 },
+ { SYS_DESC(SYS_DBGVCR32_EL2), undef_access, reset_val, DBGVCR32_EL2, 0 },

{ SYS_DESC(SYS_MPIDR_EL1), NULL, reset_mpidr, MPIDR_EL1 },

@@ -2780,7 +2760,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
EL2_REG_VNCR(VTTBR_EL2, reset_val, 0),
EL2_REG_VNCR(VTCR_EL2, reset_val, 0),

- { SYS_DESC(SYS_DACR32_EL2), trap_undef, reset_unknown, DACR32_EL2 },
+ { SYS_DESC(SYS_DACR32_EL2), undef_access, reset_unknown, DACR32_EL2 },
EL2_REG_VNCR(HDFGRTR_EL2, reset_val, 0),
EL2_REG_VNCR(HDFGWTR_EL2, reset_val, 0),
EL2_REG_VNCR(HAFGRTR_EL2, reset_val, 0),
@@ -2798,11 +2778,11 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ SYS_DESC(SYS_SPSR_fiq), .access = trap_raz_wi,
.visibility = hidden_user_visibility },

- { SYS_DESC(SYS_IFSR32_EL2), trap_undef, reset_unknown, IFSR32_EL2 },
+ { SYS_DESC(SYS_IFSR32_EL2), undef_access, reset_unknown, IFSR32_EL2 },
EL2_REG(AFSR0_EL2, access_rw, reset_val, 0),
EL2_REG(AFSR1_EL2, access_rw, reset_val, 0),
EL2_REG_REDIR(ESR_EL2, reset_val, 0),
- { SYS_DESC(SYS_FPEXC32_EL2), trap_undef, reset_val, FPEXC32_EL2, 0x700 },
+ { SYS_DESC(SYS_FPEXC32_EL2), undef_access, reset_val, FPEXC32_EL2, 0x700 },

EL2_REG_REDIR(FAR_EL2, reset_val, 0),
EL2_REG(HPFAR_EL2, access_rw, reset_val, 0),
@@ -2812,7 +2792,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {

EL2_REG(VBAR_EL2, access_rw, reset_val, 0),
EL2_REG(RVBAR_EL2, access_rw, reset_val, 0),
- { SYS_DESC(SYS_RMR_EL2), trap_undef },
+ { SYS_DESC(SYS_RMR_EL2), undef_access },

EL2_REG_VNCR(ICH_HCR_EL2, reset_val, 0),

@@ -2848,10 +2828,8 @@ static bool handle_alle1is(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
{
u32 sys_encoding = sys_insn(p->Op0, p->Op1, p->CRn, p->CRm, p->Op2);

- if (!kvm_supported_tlbi_s12_op(vcpu, sys_encoding)) {
- kvm_inject_undefined(vcpu);
- return false;
- }
+ if (!kvm_supported_tlbi_s12_op(vcpu, sys_encoding))
+ return undef_access(vcpu, p, r);

write_lock(&vcpu->kvm->mmu_lock);

@@ -2920,10 +2898,8 @@ static bool handle_vmalls12e1is(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
u32 sys_encoding = sys_insn(p->Op0, p->Op1, p->CRn, p->CRm, p->Op2);
u64 limit, vttbr;

- if (!kvm_supported_tlbi_s12_op(vcpu, sys_encoding)) {
- kvm_inject_undefined(vcpu);
- return false;
- }
+ if (!kvm_supported_tlbi_s12_op(vcpu, sys_encoding))
+ return undef_access(vcpu, p, r);

vttbr = vcpu_read_sys_reg(vcpu, VTTBR_EL2);
limit = BIT_ULL(kvm_get_pa_bits(vcpu->kvm));
@@ -2948,10 +2924,8 @@ static bool handle_ripas2e1is(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
u64 base, range, tg, num, scale;
int shift;

- if (!kvm_supported_tlbi_ipas2_op(vcpu, sys_encoding)) {
- kvm_inject_undefined(vcpu);
- return false;
- }
+ if (!kvm_supported_tlbi_ipas2_op(vcpu, sys_encoding))
+ return undef_access(vcpu, p, r);

/*
* Because the shadow S2 structure doesn't necessarily reflect that
@@ -3019,10 +2993,8 @@ static bool handle_ipas2e1is(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
u32 sys_encoding = sys_insn(p->Op0, p->Op1, p->CRn, p->CRm, p->Op2);
u64 vttbr = vcpu_read_sys_reg(vcpu, VTTBR_EL2);

- if (!kvm_supported_tlbi_ipas2_op(vcpu, sys_encoding)) {
- kvm_inject_undefined(vcpu);
- return false;
- }
+ if (!kvm_supported_tlbi_ipas2_op(vcpu, sys_encoding))
+ return undef_access(vcpu, p, r);

kvm_s2_mmu_iterate_by_vmid(vcpu->kvm, get_vmid(vttbr),
&(union tlbi_info) {
@@ -3062,10 +3034,8 @@ static bool handle_tlbi_el1(struct kvm_vcpu *vcpu, struct sys_reg_params *p,

WARN_ON(!vcpu_is_el2(vcpu));

- if (!kvm_supported_tlbi_s1e1_op(vcpu, sys_encoding)) {
- kvm_inject_undefined(vcpu);
- return false;
- }
+ if (!kvm_supported_tlbi_s1e1_op(vcpu, sys_encoding))
+ return undef_access(vcpu, p, r);

kvm_s2_mmu_iterate_by_vmid(vcpu->kvm, get_vmid(vttbr),
&(union tlbi_info) {
@@ -3173,14 +3143,14 @@ static struct sys_reg_desc sys_insn_descs[] = {
SYS_INSN(TLBI_IPAS2LE1IS, handle_ipas2e1is),
SYS_INSN(TLBI_RIPAS2LE1IS, handle_ripas2e1is),

- SYS_INSN(TLBI_ALLE2OS, trap_undef),
- SYS_INSN(TLBI_VAE2OS, trap_undef),
+ SYS_INSN(TLBI_ALLE2OS, undef_access),
+ SYS_INSN(TLBI_VAE2OS, undef_access),
SYS_INSN(TLBI_ALLE1OS, handle_alle1is),
- SYS_INSN(TLBI_VALE2OS, trap_undef),
+ SYS_INSN(TLBI_VALE2OS, undef_access),
SYS_INSN(TLBI_VMALLS12E1OS, handle_vmalls12e1is),

- SYS_INSN(TLBI_RVAE2IS, trap_undef),
- SYS_INSN(TLBI_RVALE2IS, trap_undef),
+ SYS_INSN(TLBI_RVAE2IS, undef_access),
+ SYS_INSN(TLBI_RVALE2IS, undef_access),

SYS_INSN(TLBI_ALLE1IS, handle_alle1is),
SYS_INSN(TLBI_VMALLS12E1IS, handle_vmalls12e1is),
@@ -3192,10 +3162,10 @@ static struct sys_reg_desc sys_insn_descs[] = {
SYS_INSN(TLBI_IPAS2LE1, handle_ipas2e1is),
SYS_INSN(TLBI_RIPAS2LE1, handle_ripas2e1is),
SYS_INSN(TLBI_RIPAS2LE1OS, handle_ripas2e1is),
- SYS_INSN(TLBI_RVAE2OS, trap_undef),
- SYS_INSN(TLBI_RVALE2OS, trap_undef),
- SYS_INSN(TLBI_RVAE2, trap_undef),
- SYS_INSN(TLBI_RVALE2, trap_undef),
+ SYS_INSN(TLBI_RVAE2OS, undef_access),
+ SYS_INSN(TLBI_RVALE2OS, undef_access),
+ SYS_INSN(TLBI_RVAE2, undef_access),
+ SYS_INSN(TLBI_RVALE2, undef_access),
SYS_INSN(TLBI_ALLE1, handle_alle1is),
SYS_INSN(TLBI_VMALLS12E1, handle_vmalls12e1is),

@@ -3204,19 +3174,19 @@ static struct sys_reg_desc sys_insn_descs[] = {
SYS_INSN(TLBI_IPAS2LE1ISNXS, handle_ipas2e1is),
SYS_INSN(TLBI_RIPAS2LE1ISNXS, handle_ripas2e1is),

- SYS_INSN(TLBI_ALLE2OSNXS, trap_undef),
- SYS_INSN(TLBI_VAE2OSNXS, trap_undef),
+ SYS_INSN(TLBI_ALLE2OSNXS, undef_access),
+ SYS_INSN(TLBI_VAE2OSNXS, undef_access),
SYS_INSN(TLBI_ALLE1OSNXS, handle_alle1is),
- SYS_INSN(TLBI_VALE2OSNXS, trap_undef),
+ SYS_INSN(TLBI_VALE2OSNXS, undef_access),
SYS_INSN(TLBI_VMALLS12E1OSNXS, handle_vmalls12e1is),

- SYS_INSN(TLBI_RVAE2ISNXS, trap_undef),
- SYS_INSN(TLBI_RVALE2ISNXS, trap_undef),
- SYS_INSN(TLBI_ALLE2ISNXS, trap_undef),
- SYS_INSN(TLBI_VAE2ISNXS, trap_undef),
+ SYS_INSN(TLBI_RVAE2ISNXS, undef_access),
+ SYS_INSN(TLBI_RVALE2ISNXS, undef_access),
+ SYS_INSN(TLBI_ALLE2ISNXS, undef_access),
+ SYS_INSN(TLBI_VAE2ISNXS, undef_access),

SYS_INSN(TLBI_ALLE1ISNXS, handle_alle1is),
- SYS_INSN(TLBI_VALE2ISNXS, trap_undef),
+ SYS_INSN(TLBI_VALE2ISNXS, undef_access),
SYS_INSN(TLBI_VMALLS12E1ISNXS, handle_vmalls12e1is),
SYS_INSN(TLBI_IPAS2E1OSNXS, handle_ipas2e1is),
SYS_INSN(TLBI_IPAS2E1NXS, handle_ipas2e1is),
@@ -3226,14 +3196,14 @@ static struct sys_reg_desc sys_insn_descs[] = {
SYS_INSN(TLBI_IPAS2LE1NXS, handle_ipas2e1is),
SYS_INSN(TLBI_RIPAS2LE1NXS, handle_ripas2e1is),
SYS_INSN(TLBI_RIPAS2LE1OSNXS, handle_ripas2e1is),
- SYS_INSN(TLBI_RVAE2OSNXS, trap_undef),
- SYS_INSN(TLBI_RVALE2OSNXS, trap_undef),
- SYS_INSN(TLBI_RVAE2NXS, trap_undef),
- SYS_INSN(TLBI_RVALE2NXS, trap_undef),
- SYS_INSN(TLBI_ALLE2NXS, trap_undef),
- SYS_INSN(TLBI_VAE2NXS, trap_undef),
+ SYS_INSN(TLBI_RVAE2OSNXS, undef_access),
+ SYS_INSN(TLBI_RVALE2OSNXS, undef_access),
+ SYS_INSN(TLBI_RVAE2NXS, undef_access),
+ SYS_INSN(TLBI_RVALE2NXS, undef_access),
+ SYS_INSN(TLBI_ALLE2NXS, undef_access),
+ SYS_INSN(TLBI_VAE2NXS, undef_access),
SYS_INSN(TLBI_ALLE1NXS, handle_alle1is),
- SYS_INSN(TLBI_VALE2NXS, trap_undef),
+ SYS_INSN(TLBI_VALE2NXS, undef_access),
SYS_INSN(TLBI_VMALLS12E1NXS, handle_vmalls12e1is),
};

--
2.39.2