Emulating AT A12E[01] instructions involves two steps. First, do the
stage-1 translation by reusing the existing AT emulation functions. Then
do the stage-2 translation by walking the guest hypervisor's stage-2
page table in software. Record the translation result to PAR_EL1.
Signed-off-by: Jintack Lim <jintack.lim@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_arm.h | 1 +
arch/arm64/kvm/sys_regs.c | 99 ++++++++++++++++++++++++++++++++++++++--
2 files changed, 96 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 3993703..e160895 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -111,6 +111,7 @@
#define VTCR_EL2_TG0_16K TCR_TG0_16K
#define VTCR_EL2_TG0_64K TCR_TG0_64K
#define VTCR_EL2_SH0_MASK TCR_SH0_MASK
+#define VTCR_EL2_SH0_SHIFT TCR_SH0_SHIFT
#define VTCR_EL2_SH0_INNER TCR_SH0_INNER
#define VTCR_EL2_ORGN0_MASK TCR_ORGN0_MASK
#define VTCR_EL2_ORGN0_WBWA TCR_ORGN0_WBWA
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index cb46db5..7950ee0 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1656,6 +1656,97 @@ static bool handle_s1e2(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
return true;
}
+static u64 setup_par_aborted(u32 esr)
+{
+ u64 par = 0;
+
+ /* S [9]: fault in the stage 2 translation */
+ par |= (1 << 9);
+ /* FST [6:1]: Fault status code */
+ par |= (esr << 1);
+ /* F [0]: translation is aborted */
+ par |= 1;
+
+ return par;
+}
+
+static u64 setup_par_completed(struct kvm_vcpu *vcpu, struct kvm_s2_trans *out)
+{
+ u64 par, vtcr_sh0;
+
+ /* F [0]: Translation is completed successfully */
+ par = 0;
+ /* ATTR [63:56] */
+ par |= out->upper_attr;
+ /* PA [47:12] */
+ par |= out->output & GENMASK_ULL(11, 0);
+ /* RES1 [11] */
+ par |= (1UL << 11);
+ /* SH [8:7]: Shareability attribute */
+ vtcr_sh0 = vcpu_sys_reg(vcpu, VTCR_EL2) & VTCR_EL2_SH0_MASK;
+ par |= (vtcr_sh0 >> VTCR_EL2_SH0_SHIFT) << 7;
+
+ return par;
+}
+
+static bool handle_s12(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
+ const struct sys_reg_desc *r, bool write)
+{
+ u64 par, va;
+ u32 esr;
+ phys_addr_t ipa;
+ struct kvm_s2_trans out;
+ int ret;
+
+ /* Do the stage-1 translation */
+ handle_s1e01(vcpu, p, r);
+ par = vcpu_sys_reg(vcpu, PAR_EL1);
+ if (par & 1) {
+ /* The stage-1 translation aborted */
+ return true;
+ }
+
+ /* Do the stage-2 translation */
+ va = p->regval;
+ ipa = (par & GENMASK_ULL(47, 12)) | (va & GENMASK_ULL(11, 0));
+ out.esr = 0;
+ ret = kvm_walk_nested_s2(vcpu, ipa, &out);
+ if (ret < 0)
+ return false;
+
+ /* Check if the stage-2 PTW is aborted */
+ if (out.esr) {
+ esr = out.esr;
+ goto s2_trans_abort;
+ }
+
+ /* Check the access permission */
+ if ((!write && !out.readable) || (write && !out.writable)) {
+ esr = ESR_ELx_FSC_PERM;
+ esr |= out.level & 0x3;
+ goto s2_trans_abort;
+ }
+
+ vcpu_sys_reg(vcpu, PAR_EL1) = setup_par_completed(vcpu, &out);
+ return true;
+
+s2_trans_abort:
+ vcpu_sys_reg(vcpu, PAR_EL1) = setup_par_aborted(esr);
+ return true;
+}
+
+static bool handle_s12r(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ return handle_s12(vcpu, p, r, false);
+}
+
+static bool handle_s12w(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ return handle_s12(vcpu, p, r, true);
+}
+
/*
* AT instruction emulation
*
@@ -1733,10 +1824,10 @@ static bool handle_s1e2(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
SYS_INSN_TO_DESC(AT_S1E1WP, handle_s1e01, NULL),
SYS_INSN_TO_DESC(AT_S1E2R, handle_s1e2, NULL),
SYS_INSN_TO_DESC(AT_S1E2W, handle_s1e2, NULL),
- SYS_INSN_TO_DESC(AT_S12E1R, NULL, NULL),
- SYS_INSN_TO_DESC(AT_S12E1W, NULL, NULL),
- SYS_INSN_TO_DESC(AT_S12E0R, NULL, NULL),
- SYS_INSN_TO_DESC(AT_S12E0W, NULL, NULL),
+ SYS_INSN_TO_DESC(AT_S12E1R, handle_s12r, NULL),
+ SYS_INSN_TO_DESC(AT_S12E1W, handle_s12w, NULL),
+ SYS_INSN_TO_DESC(AT_S12E0R, handle_s12r, NULL),
+ SYS_INSN_TO_DESC(AT_S12E0W, handle_s12w, NULL),
SYS_INSN_TO_DESC(TLBI_IPAS2E1IS, NULL, NULL),
SYS_INSN_TO_DESC(TLBI_IPAS2LE1IS, NULL, NULL),
SYS_INSN_TO_DESC(TLBI_ALLE2IS, NULL, NULL),
--
1.9.1
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