SME is configured by the system registers SMCR_EL1 and SMCR_EL2, add
definitions and userspace access for them.  These control the SME vector
length in a manner similar to that for SVE and also have feature enable
bits for SME2 and FA64.  A subsequent patch will add management of them
for guests as part of the general floating point context switch, as is
done for the equivalent SVE registers.

Signed-off-by: Mark Brown <broo...@kernel.org>
---
 arch/arm64/include/asm/kvm_host.h     |  2 ++
 arch/arm64/include/asm/vncr_mapping.h |  1 +
 arch/arm64/kvm/sys_regs.c             | 37 ++++++++++++++++++++++++++++++++++-
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/kvm_host.h 
b/arch/arm64/include/asm/kvm_host.h
index 4348f297b5ae..edb2acdb4bd1 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -506,6 +506,7 @@ enum vcpu_sysreg {
        CPTR_EL2,       /* Architectural Feature Trap Register (EL2) */
        HACR_EL2,       /* Hypervisor Auxiliary Control Register */
        ZCR_EL2,        /* SVE Control Register (EL2) */
+       SMCR_EL2,       /* SME Control Register (EL2) */
        TTBR0_EL2,      /* Translation Table Base Register 0 (EL2) */
        TTBR1_EL2,      /* Translation Table Base Register 1 (EL2) */
        TCR_EL2,        /* Translation Control Register (EL2) */
@@ -544,6 +545,7 @@ enum vcpu_sysreg {
        VNCR(ACTLR_EL1),/* Auxiliary Control Register */
        VNCR(CPACR_EL1),/* Coprocessor Access Control */
        VNCR(ZCR_EL1),  /* SVE Control */
+       VNCR(SMCR_EL1), /* SME Control */
        VNCR(TTBR0_EL1),/* Translation Table Base Register 0 */
        VNCR(TTBR1_EL1),/* Translation Table Base Register 1 */
        VNCR(TCR_EL1),  /* Translation Control Register */
diff --git a/arch/arm64/include/asm/vncr_mapping.h 
b/arch/arm64/include/asm/vncr_mapping.h
index f6ec500ad3fa..5ab6a964bccf 100644
--- a/arch/arm64/include/asm/vncr_mapping.h
+++ b/arch/arm64/include/asm/vncr_mapping.h
@@ -44,6 +44,7 @@
 #define VNCR_HDFGWTR_EL2       0x1D8
 #define VNCR_ZCR_EL1            0x1E0
 #define VNCR_HAFGRTR_EL2       0x1E8
+#define VNCR_SMCR_EL1          0x1F0
 #define VNCR_TTBR0_EL1          0x200
 #define VNCR_TTBR1_EL1          0x210
 #define VNCR_FAR_EL1            0x220
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 111b07a78787..81742e9237c0 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -142,6 +142,7 @@ static bool get_el2_to_el1_mapping(unsigned int reg,
                MAPPED_EL2_SYSREG(ELR_EL2,     ELR_EL1,     NULL             );
                MAPPED_EL2_SYSREG(SPSR_EL2,    SPSR_EL1,    NULL             );
                MAPPED_EL2_SYSREG(ZCR_EL2,     ZCR_EL1,     NULL             );
+               MAPPED_EL2_SYSREG(SMCR_EL2,    SMCR_EL1,    NULL             );
                MAPPED_EL2_SYSREG(CONTEXTIDR_EL2, CONTEXTIDR_EL1, NULL       );
                MAPPED_EL2_SYSREG(SCTLR2_EL2,  SCTLR2_EL1,  NULL             );
        default:
@@ -2589,6 +2590,37 @@ static bool access_gic_elrsr(struct kvm_vcpu *vcpu,
        return true;
 }
 
+static unsigned int sme_el2_visibility(const struct kvm_vcpu *vcpu,
+                                      const struct sys_reg_desc *rd)
+{
+       return __el2_visibility(vcpu, rd, sme_visibility);
+}
+
+static bool access_smcr_el2(struct kvm_vcpu *vcpu,
+                           struct sys_reg_params *p,
+                           const struct sys_reg_desc *r)
+{
+       unsigned int vq;
+       u64 smcr;
+
+       if (guest_hyp_sve_traps_enabled(vcpu)) {
+               kvm_inject_nested_sve_trap(vcpu);
+               return true;
+       }
+
+       if (!p->is_write) {
+               p->regval = vcpu_read_sys_reg(vcpu, SMCR_EL2);
+               return true;
+       }
+
+       smcr = p->regval;
+       vq = SYS_FIELD_GET(SMCR_ELx, LEN, smcr) + 1;
+       vq = min(vq, vcpu_sme_max_vq(vcpu));
+       vcpu_write_sys_reg(vcpu, SYS_FIELD_PREP(SMCR_ELx, LEN, vq - 1),
+                          SMCR_EL2);
+       return true;
+}
+
 static unsigned int s1poe_visibility(const struct kvm_vcpu *vcpu,
                                     const struct sys_reg_desc *rd)
 {
@@ -3035,7 +3067,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
        { SYS_DESC(SYS_ZCR_EL1), NULL, reset_val, ZCR_EL1, 0, .visibility = 
sve_visibility },
        { SYS_DESC(SYS_TRFCR_EL1), undef_access },
        { SYS_DESC(SYS_SMPRI_EL1), undef_access },
-       { SYS_DESC(SYS_SMCR_EL1), undef_access },
+       { SYS_DESC(SYS_SMCR_EL1), NULL, reset_val, SMCR_EL1, 0, .visibility = 
sme_visibility },
        { SYS_DESC(SYS_TTBR0_EL1), access_vm_reg, reset_unknown, TTBR0_EL1 },
        { SYS_DESC(SYS_TTBR1_EL1), access_vm_reg, reset_unknown, TTBR1_EL1 },
        { SYS_DESC(SYS_TCR_EL1), access_vm_reg, reset_val, TCR_EL1, 0 },
@@ -3391,6 +3423,9 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 
        EL2_REG_VNCR(HCRX_EL2, reset_val, 0),
 
+       EL2_REG_FILTERED(SMCR_EL2, access_smcr_el2, reset_val, 0,
+                        sme_el2_visibility),
+
        EL2_REG(TTBR0_EL2, access_rw, reset_val, 0),
        EL2_REG(TTBR1_EL2, access_rw, reset_val, 0),
        EL2_REG(TCR_EL2, access_rw, reset_val, TCR_EL2_RES1),

-- 
2.39.5


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