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From: Marc Zyngier <marc.zyngier@arm.com>
To: linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: Andre Przywara <andre.przywara@arm.com>,
	Dave Martin <Dave.Martin@arm.com>
Subject: [PATCH 43/59] KVM: arm64: nv: Trap and emulate AT instructions from virtual EL2
Date: Fri, 21 Jun 2019 10:38:27 +0100
Message-ID: <20190621093843.220980-44-marc.zyngier@arm.com> (raw)
In-Reply-To: <20190621093843.220980-1-marc.zyngier@arm.com>

From: Jintack Lim <jintack.lim@linaro.org>

When supporting nested virtualization a guest hypervisor executing AT
instructions must be trapped and emulated by the host hypervisor,
because untrapped AT instructions operating on S1E1 will use the wrong
translation regieme (the one used to emulate virtual EL2 in EL1 instead
of virtual EL1) and AT instructions operating on S12 will not work from
EL1.

This patch does several things.

1. List and define all AT system instructions to emulate and document
the emulation design.

2. Implement AT instruction handling logic in EL2. This will be used to
emulate AT instructions executed in the virtual EL2.

AT instruction emulation works by loading the proper processor
context, which depends on the trapped instruction and the virtual
HCR_EL2, to the EL1 virtual memory control registers and executing AT
instructions. Note that ctxt->hw_sys_regs is expected to have the
proper processor context before calling the handling
function(__kvm_at_insn) implemented in this patch.

4. Emulate AT S1E[01] instructions by issuing the same instructions in
EL2. We set the physical EL1 registers, NV and NV1 bits as described in
the AT instruction emulation overview.

5. Emulate AT A12E[01] instructions in two steps: First, do the stage-1
translation by reusing the existing AT emulation functions.  Second, do
the stage-2 translation by walking the guest hypervisor's stage-2 page
table in software. Record the translation result to PAR_EL1.

6. Emulate AT S1E2 instructions by issuing the corresponding S1E1
instructions in EL2. We set the physical EL1 registers and the HCR_EL2
register as described in the AT instruction emulation overview.

7. Forward system instruction traps to the virtual EL2 if the corresponding
virtual AT bit is set in the virtual HCR_EL2.

  [ Much logic above has been reworked by Marc Zyngier ]

Signed-off-by: Jintack Lim <jintack.lim@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
---
 arch/arm64/include/asm/kvm_arm.h |   2 +
 arch/arm64/include/asm/kvm_asm.h |   2 +
 arch/arm64/include/asm/sysreg.h  |  17 +++
 arch/arm64/kvm/hyp/Makefile      |   1 +
 arch/arm64/kvm/hyp/at.c          | 217 +++++++++++++++++++++++++++++++
 arch/arm64/kvm/hyp/switch.c      |  13 +-
 arch/arm64/kvm/sys_regs.c        | 202 +++++++++++++++++++++++++++-
 7 files changed, 450 insertions(+), 4 deletions(-)
 create mode 100644 arch/arm64/kvm/hyp/at.c

diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 1e4dbe0b1c8e..9903f10f6343 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -24,6 +24,7 @@
 
 /* Hyp Configuration Register (HCR) bits */
 #define HCR_FWB		(UL(1) << 46)
+#define HCR_AT		(UL(1) << 44)
 #define HCR_NV1		(UL(1) << 43)
 #define HCR_NV		(UL(1) << 42)
 #define HCR_API		(UL(1) << 41)
@@ -119,6 +120,7 @@
 #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/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 5e956c2cd9b4..1cfa4d2cf772 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -69,6 +69,8 @@ extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
 extern void __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu);
 
 extern void __kvm_timer_set_cntvoff(u32 cntvoff_low, u32 cntvoff_high);
+extern void __kvm_at_s1e01(struct kvm_vcpu *vcpu, u32 op, u64 vaddr);
+extern void __kvm_at_s1e2(struct kvm_vcpu *vcpu, u32 op, u64 vaddr);
 
 extern int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu);
 
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 8b95f2c42c3d..b3a8d21c07b3 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -536,6 +536,23 @@
 
 #define SYS_SP_EL2			sys_reg(3, 6,  4, 1, 0)
 
+/* AT instructions */
+#define AT_Op0 1
+#define AT_CRn 7
+
+#define OP_AT_S1E1R	sys_insn(AT_Op0, 0, AT_CRn, 8, 0)
+#define OP_AT_S1E1W	sys_insn(AT_Op0, 0, AT_CRn, 8, 1)
+#define OP_AT_S1E0R	sys_insn(AT_Op0, 0, AT_CRn, 8, 2)
+#define OP_AT_S1E0W	sys_insn(AT_Op0, 0, AT_CRn, 8, 3)
+#define OP_AT_S1E1RP	sys_insn(AT_Op0, 0, AT_CRn, 9, 0)
+#define OP_AT_S1E1WP	sys_insn(AT_Op0, 0, AT_CRn, 9, 1)
+#define OP_AT_S1E2R	sys_insn(AT_Op0, 4, AT_CRn, 8, 0)
+#define OP_AT_S1E2W	sys_insn(AT_Op0, 4, AT_CRn, 8, 1)
+#define OP_AT_S12E1R	sys_insn(AT_Op0, 4, AT_CRn, 8, 4)
+#define OP_AT_S12E1W	sys_insn(AT_Op0, 4, AT_CRn, 8, 5)
+#define OP_AT_S12E0R	sys_insn(AT_Op0, 4, AT_CRn, 8, 6)
+#define OP_AT_S12E0W	sys_insn(AT_Op0, 4, AT_CRn, 8, 7)
+
 /* Common SCTLR_ELx flags. */
 #define SCTLR_ELx_DSSBS	(_BITUL(44))
 #define SCTLR_ELx_ENIA	(_BITUL(31))
diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
index ea710f674cb6..f7af51647079 100644
--- a/arch/arm64/kvm/hyp/Makefile
+++ b/arch/arm64/kvm/hyp/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_KVM_ARM_HOST) += entry.o
 obj-$(CONFIG_KVM_ARM_HOST) += switch.o
 obj-$(CONFIG_KVM_ARM_HOST) += fpsimd.o
 obj-$(CONFIG_KVM_ARM_HOST) += tlb.o
+obj-$(CONFIG_KVM_ARM_HOST) += at.o
 obj-$(CONFIG_KVM_ARM_HOST) += hyp-entry.o
 
 # KVM code is run at a different exception code with a different map, so
diff --git a/arch/arm64/kvm/hyp/at.c b/arch/arm64/kvm/hyp/at.c
new file mode 100644
index 000000000000..0e938b6f8e43
--- /dev/null
+++ b/arch/arm64/kvm/hyp/at.c
@@ -0,0 +1,217 @@
+/*
+ * Copyright (C) 2017 - Linaro Ltd
+ * Author: Jintack Lim <jintack.lim@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <asm/kvm_hyp.h>
+#include <asm/kvm_mmu.h>
+
+struct mmu_config {
+	u64	ttbr0;
+	u64	ttbr1;
+	u64	tcr;
+	u64	sctlr;
+	u64	vttbr;
+	u64	vtcr;
+	u64	hcr;
+};
+
+static void __mmu_config_save(struct mmu_config *config)
+{
+	config->ttbr0	= read_sysreg_el1(SYS_TTBR0);
+	config->ttbr1	= read_sysreg_el1(SYS_TTBR1);
+	config->tcr	= read_sysreg_el1(SYS_TCR);
+	config->sctlr	= read_sysreg_el1(SYS_SCTLR);
+	config->vttbr	= read_sysreg(vttbr_el2);
+	config->vtcr	= read_sysreg(vtcr_el2);
+	config->hcr	= read_sysreg(hcr_el2);
+}
+
+static void __mmu_config_restore(struct mmu_config *config)
+{
+	write_sysreg_el1(config->ttbr0,	SYS_TTBR0);
+	write_sysreg_el1(config->ttbr1,	SYS_TTBR1);
+	write_sysreg_el1(config->tcr,	SYS_TCR);
+	write_sysreg_el1(config->sctlr,	SYS_SCTLR);
+	write_sysreg(config->vttbr,	vttbr_el2);
+	write_sysreg(config->vtcr,	vttbr_el2);
+	write_sysreg(config->hcr,	hcr_el2);
+
+	isb();
+}
+
+void __kvm_at_s1e01(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
+{
+	struct kvm_cpu_context *ctxt = &vcpu->arch.ctxt;
+	struct mmu_config config;
+	struct kvm_s2_mmu *mmu;
+
+	/*
+	 * We can only get here when trapping from vEL2, so we're
+	 * translating a guest guest VA.
+	 *
+	 * FIXME: Obtaining the S2 MMU for a a guest guest is horribly
+	 * racy, and we may not find it.
+	 */
+	spin_lock(&vcpu->kvm->mmu_lock);
+
+	mmu = lookup_s2_mmu(vcpu->kvm,
+			    vcpu_read_sys_reg(vcpu, VTTBR_EL2),
+			    vcpu_read_sys_reg(vcpu, HCR_EL2));
+
+	if (WARN_ON(!mmu))
+		goto out;
+
+	/* We've trapped, so everything is live on the CPU. */
+	__mmu_config_save(&config);
+
+	write_sysreg_el1(ctxt->sys_regs[TTBR0_EL1],	SYS_TTBR0);
+	write_sysreg_el1(ctxt->sys_regs[TTBR1_EL1],	SYS_TTBR1);
+	write_sysreg_el1(ctxt->sys_regs[TCR_EL1],	SYS_TCR);
+	write_sysreg_el1(ctxt->sys_regs[SCTLR_EL1],	SYS_SCTLR);
+	write_sysreg(kvm_get_vttbr(mmu),		vttbr_el2);
+	/* FIXME: write S2 MMU VTCR_EL2 */
+	write_sysreg(config.hcr & ~HCR_TGE,		hcr_el2);
+
+	isb();
+
+	switch (op) {
+	case OP_AT_S1E1R:
+	case OP_AT_S1E1RP:
+		asm volatile("at s1e1r, %0" : : "r" (vaddr));
+		break;
+	case OP_AT_S1E1W:
+	case OP_AT_S1E1WP:
+		asm volatile("at s1e1w, %0" : : "r" (vaddr));
+		break;
+	case OP_AT_S1E0R:
+		asm volatile("at s1e0r, %0" : : "r" (vaddr));
+		break;
+	case OP_AT_S1E0W:
+		asm volatile("at s1e0w, %0" : : "r" (vaddr));
+		break;
+	default:
+		WARN_ON(1);
+		break;
+	}
+
+	isb();
+
+	ctxt->sys_regs[PAR_EL1] = read_sysreg(par_el1);
+
+	/*
+	 * Failed? let's leave the building now.
+	 *
+	 * FIXME: how about a failed translation because the shadow S2
+	 * wasn't populated? We may need to perform a SW PTW,
+	 * populating our shadow S2 and retry the instruction.
+	 */
+	if (ctxt->sys_regs[PAR_EL1] & 1)
+		goto nopan;
+
+	/* No PAN? No problem. */
+	if (!(*vcpu_cpsr(vcpu) & PSR_PAN_BIT))
+		goto nopan;
+
+	/*
+	 * For PAN-involved AT operations, perform the same
+	 * translation, using EL0 this time.
+	 */
+	switch (op) {
+	case OP_AT_S1E1RP:
+		asm volatile("at s1e0r, %0" : : "r" (vaddr));
+		break;
+	case OP_AT_S1E1WP:
+		asm volatile("at s1e0w, %0" : : "r" (vaddr));
+		break;
+	default:
+		goto nopan;
+	}
+
+	/*
+	 * If the EL0 translation has succeeded, we need to pretend
+	 * the AT operation has failed, as the PAN setting forbids
+	 * such a translation.
+	 *
+	 * FIXME: we hardcode a Level-3 permission fault. We really
+	 * should return the real fault level.
+	 */
+	if (!(read_sysreg(par_el1) & 1))
+		ctxt->sys_regs[PAR_EL1] = 0x1f;
+
+nopan:
+	__mmu_config_restore(&config);
+
+out:
+	spin_unlock(&vcpu->kvm->mmu_lock);
+}
+
+void __kvm_at_s1e2(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
+{
+	struct kvm_cpu_context *ctxt = &vcpu->arch.ctxt;
+	struct mmu_config config;
+	struct kvm_s2_mmu *mmu;
+	u64 val;
+
+	spin_lock(&vcpu->kvm->mmu_lock);
+
+	mmu = &vcpu->kvm->arch.mmu;
+
+	/* We've trapped, so everything is live on the CPU. */
+	__mmu_config_save(&config);
+
+	if (vcpu_el2_e2h_is_set(vcpu)) {
+		write_sysreg_el1(ctxt->sys_regs[TTBR0_EL2],	SYS_TTBR0);
+		write_sysreg_el1(ctxt->sys_regs[TTBR1_EL2],	SYS_TTBR1);
+		write_sysreg_el1(ctxt->sys_regs[TCR_EL2],	SYS_TCR);
+		write_sysreg_el1(ctxt->sys_regs[SCTLR_EL2],	SYS_SCTLR);
+
+		val = config.hcr;
+	} else {
+		write_sysreg_el1(ctxt->sys_regs[TTBR0_EL2],	SYS_TTBR0);
+		write_sysreg_el1(translate_tcr(ctxt->sys_regs[TCR_EL2]),
+				 SYS_TCR);
+		write_sysreg_el1(translate_sctlr(ctxt->sys_regs[SCTLR_EL2]),
+				 SYS_SCTLR);
+
+		val = config.hcr | HCR_NV | HCR_NV1;
+	}
+
+	write_sysreg(kvm_get_vttbr(mmu),		vttbr_el2);
+	/* FIXME: write S2 MMU VTCR_EL2 */
+	write_sysreg(val & ~HCR_TGE,			hcr_el2);
+
+	isb();
+
+	switch (op) {
+	case OP_AT_S1E2R:
+		asm volatile("at s1e1r, %0" : : "r" (vaddr));
+		break;
+	case OP_AT_S1E2W:
+		asm volatile("at s1e1w, %0" : : "r" (vaddr));
+		break;
+	default:
+		WARN_ON(1);
+		break;
+	}
+
+	isb();
+
+	/* FIXME: handle failed translation due to shadow S2 */
+	ctxt->sys_regs[PAR_EL1] = read_sysreg(par_el1);
+
+	__mmu_config_restore(&config);
+	spin_unlock(&vcpu->kvm->mmu_lock);
+}
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index fb479c71b521..bd9fc0dae8e8 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -143,9 +143,10 @@ static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu)
 		if (!vcpu_el2_e2h_is_set(vcpu)) {
 			/*
 			 * For a guest hypervisor on v8.0, trap and emulate
-			 * the EL1 virtual memory control register accesses.
+			 * the EL1 virtual memory control register accesses
+			 * as well as the AT S1 operations.
 			 */
-			hcr |= HCR_TVM | HCR_TRVM | HCR_NV1;
+			hcr |= HCR_TVM | HCR_TRVM | HCR_AT | HCR_NV1;
 		} else {
 			/*
 			 * For a guest hypervisor on v8.1 (VHE), allow to
@@ -168,6 +169,14 @@ static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu)
 			hcr &= ~HCR_TVM;
 
 			hcr |= vhcr_el2 & (HCR_TVM | HCR_TRVM);
+
+			/*
+			 * If we're using the EL1 translation regime
+			 * (TGE clear, then ensure that AT S1 ops are
+			 * trapped too.
+			 */
+			if (!vcpu_el2_tge_is_set(vcpu))
+				hcr |= HCR_AT;
 		}
 	}
 
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 0d5b7a7c76de..102419b837e8 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1656,6 +1656,11 @@ static bool access_sp_el1(struct kvm_vcpu *vcpu,
 	return true;
 }
 
+static bool forward_at_traps(struct kvm_vcpu *vcpu)
+{
+	return forward_traps(vcpu, HCR_AT);
+}
+
 /* This function is to support the recursive nested virtualization */
 static bool forward_nv1_traps(struct kvm_vcpu *vcpu, struct sys_reg_params *p)
 {
@@ -2135,12 +2140,205 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	{ SYS_DESC(SYS_SP_EL2), NULL, reset_unknown, SP_EL2 },
 };
 
-#define SYS_INSN_TO_DESC(insn, access_fn, forward_fn)	\
-	{ SYS_DESC((insn)), (access_fn), NULL, 0, 0, NULL, NULL, (forward_fn) }
+static bool handle_s1e01(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
+			 const struct sys_reg_desc *r)
+{
+	int sys_encoding = sys_insn(p->Op0, p->Op1, p->CRn, p->CRm, p->Op2);
+
+	__kvm_at_s1e01(vcpu, sys_encoding, p->regval);
+
+	return true;
+}
+
+static bool handle_s1e2(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
+			const struct sys_reg_desc *r)
+{
+	int sys_encoding = sys_insn(p->Op0, p->Op1, p->CRn, p->CRm, p->Op2);
+
+	__kvm_at_s1e2(vcpu, sys_encoding, p->regval);
+
+	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_read_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_read_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_write_sys_reg(vcpu, setup_par_completed(vcpu, &out), PAR_EL1);
+	return true;
+
+s2_trans_abort:
+	vcpu_write_sys_reg(vcpu, setup_par_aborted(esr), PAR_EL1);
+	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
+ *
+ * We emulate AT instructions executed in the virtual EL2.
+ * Basic strategy for the stage-1 translation emulation is to load proper
+ * context, which depends on the trapped instruction and the virtual HCR_EL2,
+ * to the EL1 virtual memory control registers and execute S1E[01] instructions
+ * in EL2. See below for more detail.
+ *
+ * For the stage-2 translation, which is necessary for S12E[01] emulation,
+ * we walk the guest hypervisor's stage-2 page table in software.
+ *
+ * The stage-1 translation emulations can be divided into two groups depending
+ * on the translation regime.
+ *
+ * 1. EL2 AT instructions: S1E2x
+ * +-----------------------------------------------------------------------+
+ * |                             |         Setting for the emulation       |
+ * | Virtual HCR_EL2.E2H on trap |-----------------------------------------+
+ * |                             | Phys EL1 regs | Phys NV, NV1 | Phys TGE |
+ * |-----------------------------------------------------------------------|
+ * |             0               |     vEL2      |    (1, 1)    |    0     |
+ * |             1               |     vEL2      |    (0, 0)    |    0     |
+ * +-----------------------------------------------------------------------+
+ *
+ * We emulate the EL2 AT instructions by loading virtual EL2 context
+ * to the EL1 virtual memory control registers and executing corresponding
+ * EL1 AT instructions.
+ *
+ * We set physical NV and NV1 bits to use EL2 page table format for non-VHE
+ * guest hypervisor (i.e. HCR_EL2.E2H == 0). As a VHE guest hypervisor uses the
+ * EL1 page table format, we don't set those bits.
+ *
+ * We should clear physical TGE bit not to use the EL2 translation regime when
+ * the host uses the VHE feature.
+ *
+ *
+ * 2. EL0/EL1 AT instructions: S1E[01]x, S12E1x
+ * +----------------------------------------------------------------------+
+ * |   Virtual HCR_EL2 on trap  |        Setting for the emulation        |
+ * |----------------------------------------------------------------------+
+ * | (vE2H, vTGE) | (vNV, vNV1) | Phys EL1 regs | Phys NV, NV1 | Phys TGE |
+ * |----------------------------------------------------------------------|
+ * |    (0, 0)*   |   (0, 0)    |      vEL1     |    (0, 0)    |    0     |
+ * |    (0, 0)    |   (1, 1)    |      vEL1     |    (1, 1)    |    0     |
+ * |    (1, 1)    |   (0, 0)    |      vEL2     |    (0, 0)    |    0     |
+ * |    (1, 1)    |   (1, 1)    |      vEL2     |    (1, 1)    |    0     |
+ * +----------------------------------------------------------------------+
+ *
+ * *For (0, 0) in the 'Virtual HCR_EL2 on trap' column, it actually means
+ *  (1, 1). Keep them (0, 0) just for the readability.
+ *
+ * We set physical EL1 virtual memory control registers depending on
+ * (vE2H, vTGE) pair. When the pair is (0, 0) where AT instructions are
+ * supposed to use EL0/EL1 translation regime, we load the EL1 registers with
+ * the virtual EL1 registers (i.e. EL1 registers from the guest hypervisor's
+ * point of view). When the pair is (1, 1), however, AT instructions are defined
+ * to apply EL2 translation regime. To emulate this behavior, we load the EL1
+ * registers with the virtual EL2 context. (i.e the shadow registers)
+ *
+ * We respect the virtual NV and NV1 bit for the emulation. When those bits are
+ * set, it means that a guest hypervisor would like to use EL2 page table format
+ * for the EL1 translation regime. We emulate this by setting the physical
+ * NV and NV1 bits.
+ */
+
+#define SYS_INSN_TO_DESC(insn, access_fn, forward_fn)			\
+	{ SYS_DESC(OP_##insn), (access_fn), NULL, 0, 0,			\
+	  NULL, NULL, (forward_fn) }
 static struct sys_reg_desc sys_insn_descs[] = {
 	{ SYS_DESC(SYS_DC_ISW), access_dcsw },
+
+	SYS_INSN_TO_DESC(AT_S1E1R, handle_s1e01, forward_at_traps),
+	SYS_INSN_TO_DESC(AT_S1E1W, handle_s1e01, forward_at_traps),
+	SYS_INSN_TO_DESC(AT_S1E0R, handle_s1e01, forward_at_traps),
+	SYS_INSN_TO_DESC(AT_S1E0W, handle_s1e01, forward_at_traps),
+	SYS_INSN_TO_DESC(AT_S1E1RP, handle_s1e01, forward_at_traps),
+	SYS_INSN_TO_DESC(AT_S1E1WP, handle_s1e01, forward_at_traps),
+
 	{ SYS_DESC(SYS_DC_CSW), access_dcsw },
 	{ SYS_DESC(SYS_DC_CISW), access_dcsw },
+
+	SYS_INSN_TO_DESC(AT_S1E2R, handle_s1e2, forward_nv_traps),
+	SYS_INSN_TO_DESC(AT_S1E2W, handle_s1e2, forward_nv_traps),
+	SYS_INSN_TO_DESC(AT_S12E1R, handle_s12r, forward_nv_traps),
+	SYS_INSN_TO_DESC(AT_S12E1W, handle_s12w, forward_nv_traps),
+	SYS_INSN_TO_DESC(AT_S12E0R, handle_s12r, forward_nv_traps),
+	SYS_INSN_TO_DESC(AT_S12E0W, handle_s12w, forward_nv_traps),
 };
 
 static bool trap_dbgidr(struct kvm_vcpu *vcpu,
-- 
2.20.1

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Thread overview: 177+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-21  9:37 [PATCH 00/59] KVM: arm64: ARMv8.3 Nested Virtualization support Marc Zyngier
2019-06-21  9:37 ` [PATCH 01/59] KVM: arm64: Migrate _elx sysreg accessors to msr_s/mrs_s Marc Zyngier
2019-06-24 11:16   ` Dave Martin
2019-06-24 12:59   ` Alexandru Elisei
2019-07-03 12:32     ` Marc Zyngier
2019-06-21  9:37 ` [PATCH 02/59] KVM: arm64: Move __load_guest_stage2 to kvm_mmu.h Marc Zyngier
2019-06-24 11:19   ` Dave Martin
2019-07-03  9:30     ` Marc Zyngier
2019-07-03 16:13       ` Dave Martin
2019-06-21  9:37 ` [PATCH 03/59] arm64: Add ARM64_HAS_NESTED_VIRT cpufeature Marc Zyngier
2019-06-21 13:08   ` Julien Thierry
2019-06-21 13:22     ` Marc Zyngier
2019-06-21 13:44   ` Suzuki K Poulose
2019-06-24 11:24   ` Dave Martin
2019-06-21  9:37 ` [PATCH 04/59] KVM: arm64: nv: Introduce nested virtualization VCPU feature Marc Zyngier
2019-06-21 13:08   ` Julien Thierry
2019-06-24 11:28   ` Dave Martin
2019-07-03 11:53     ` Marc Zyngier
2019-07-03 16:27       ` Dave Martin
2019-06-24 11:43   ` Dave Martin
2019-07-03 11:56     ` Marc Zyngier
2019-07-03 16:24       ` Dave Martin
2019-06-21  9:37 ` [PATCH 05/59] KVM: arm64: nv: Reset VCPU to EL2 registers if VCPU nested virt is set Marc Zyngier
2019-06-24 10:19   ` Suzuki K Poulose
2019-06-24 11:38   ` Dave Martin
2019-06-21  9:37 ` [PATCH 06/59] KVM: arm64: nv: Allow userspace to set PSR_MODE_EL2x Marc Zyngier
2019-06-21 13:24   ` Julien Thierry
2019-06-21 13:50     ` Marc Zyngier
2019-06-24 12:48       ` Dave Martin
2019-07-03  9:21         ` Marc Zyngier
2019-07-04 10:00           ` Dave Martin
2019-06-21  9:37 ` [PATCH 07/59] KVM: arm64: nv: Add EL2 system registers to vcpu context Marc Zyngier
2019-06-24 12:54   ` Dave Martin
2019-07-03 12:20     ` Marc Zyngier
2019-07-03 16:31       ` Dave Martin
2019-06-24 15:47   ` Alexandru Elisei
2019-07-03 13:20     ` Marc Zyngier
2019-07-03 16:01       ` Marc Zyngier
2019-07-01 16:36   ` Suzuki K Poulose
2019-06-21  9:37 ` [PATCH 08/59] KVM: arm64: nv: Reset VMPIDR_EL2 and VPIDR_EL2 to sane values Marc Zyngier
2019-06-24 12:59   ` Dave Martin
2019-06-21  9:37 ` [PATCH 09/59] KVM: arm64: nv: Add nested virt VCPU primitives for vEL2 VCPU state Marc Zyngier
2019-06-24 13:08   ` Dave Martin
2019-06-21  9:37 ` [PATCH 10/59] KVM: arm64: nv: Support virtual EL2 exceptions Marc Zyngier
2019-07-08 13:56   ` Steven Price
2019-06-21  9:37 ` [PATCH 11/59] KVM: arm64: nv: Inject HVC exceptions to the virtual EL2 Marc Zyngier
2019-06-25 13:13   ` Alexandru Elisei
2019-07-03 14:16     ` Marc Zyngier
2019-07-30 14:08     ` Alexandru Elisei
2019-06-21  9:37 ` [PATCH 12/59] KVM: arm64: nv: Handle trapped ERET from " Marc Zyngier
2019-07-02 12:00   ` Alexandru Elisei
2019-06-21  9:37 ` [PATCH 13/59] KVM: arm64: nv: Handle virtual EL2 registers in vcpu_read/write_sys_reg() Marc Zyngier
2019-06-24 12:42   ` Julien Thierry
2019-06-25 14:02     ` Alexandru Elisei
2019-07-03 12:15     ` Marc Zyngier
2019-07-03 15:21       ` Julien Thierry
2019-06-25 15:18   ` Alexandru Elisei
2019-07-01  9:58     ` Alexandru Elisei
2019-07-03 15:59     ` Marc Zyngier
2019-07-03 16:32       ` Alexandru Elisei
2019-07-04 14:39         ` Marc Zyngier
2019-06-26 15:04   ` Alexandru Elisei
2019-07-04 15:05     ` Marc Zyngier
2019-07-01 12:10   ` Alexandru Elisei
2019-06-21  9:37 ` [PATCH 14/59] KVM: arm64: nv: Handle SPSR_EL2 specially Marc Zyngier
2019-06-21  9:37 ` [PATCH 15/59] KVM: arm64: nv: Refactor vcpu_{read,write}_sys_reg Marc Zyngier
2019-06-24 15:07   ` Julien Thierry
2019-07-03 13:09     ` Marc Zyngier
2019-06-27  9:21   ` Alexandru Elisei
2019-07-04 15:15     ` Marc Zyngier
2019-06-21  9:38 ` [PATCH 16/59] KVM: arm64: nv: Save/Restore vEL2 sysregs Marc Zyngier
2019-06-25  8:48   ` Julien Thierry
2019-07-03 13:42     ` Marc Zyngier
2019-07-01 12:09   ` Alexandru Elisei
2019-08-21 11:57   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 17/59] KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisor Marc Zyngier
2019-06-21  9:38 ` [PATCH 18/59] KVM: arm64: nv: Trap EL1 VM register accesses in virtual EL2 Marc Zyngier
2019-07-01 16:12   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 19/59] KVM: arm64: nv: Trap SPSR_EL1, ELR_EL1 and VBAR_EL1 from " Marc Zyngier
2019-06-21  9:38 ` [PATCH 20/59] KVM: arm64: nv: Trap CPACR_EL1 access in " Marc Zyngier
2019-07-01 16:40   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 21/59] KVM: arm64: nv: Set a handler for the system instruction traps Marc Zyngier
2019-06-25 12:55   ` Julien Thierry
2019-07-03 14:15     ` Marc Zyngier
2019-06-21  9:38 ` [PATCH 22/59] KVM: arm64: nv: Handle PSCI call via smc from the guest Marc Zyngier
2019-06-21  9:38 ` [PATCH 23/59] KVM: arm64: nv: Respect virtual HCR_EL2.TWX setting Marc Zyngier
2019-06-25 14:19   ` Julien Thierry
2019-07-02 12:54     ` Alexandru Elisei
2019-07-03 14:18     ` Marc Zyngier
2019-06-21  9:38 ` [PATCH 24/59] KVM: arm64: nv: Respect virtual CPTR_EL2.TFP setting Marc Zyngier
2019-06-21  9:38 ` [PATCH 25/59] KVM: arm64: nv: Don't expose SVE to nested guests Marc Zyngier
2019-06-21  9:38 ` [PATCH 26/59] KVM: arm64: nv: Respect the virtual HCR_EL2.NV bit setting Marc Zyngier
2019-06-26  5:31   ` Julien Thierry
2019-07-03 16:31     ` Marc Zyngier
2019-06-21  9:38 ` [PATCH 27/59] KVM: arm64: nv: Respect virtual HCR_EL2.TVM and TRVM settings Marc Zyngier
2019-06-26  6:55   ` Julien Thierry
2019-07-04 14:57     ` Marc Zyngier
2019-06-21  9:38 ` [PATCH 28/59] KVM: arm64: nv: Respect the virtual HCR_EL2.NV1 bit setting Marc Zyngier
2019-06-26  7:23   ` Julien Thierry
2019-07-02 16:32   ` Alexandru Elisei
2019-07-03  9:10     ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 29/59] KVM: arm64: nv: Emulate EL12 register accesses from the virtual EL2 Marc Zyngier
2019-07-03  9:16   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 30/59] KVM: arm64: nv: Configure HCR_EL2 for nested virtualization Marc Zyngier
2019-06-21  9:38 ` [PATCH 31/59] KVM: arm64: nv: Only toggle cache for virtual EL2 when SCTLR_EL2 changes Marc Zyngier
2019-06-21  9:38 ` [PATCH 32/59] KVM: arm64: nv: Hide RAS from nested guests Marc Zyngier
2019-07-03 13:59   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 33/59] KVM: arm64: nv: Pretend we only support larger-than-host page sizes Marc Zyngier
2019-07-03 14:13   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 34/59] KVM: arm/arm64: nv: Factor out stage 2 page table data from struct kvm Marc Zyngier
2019-07-03 15:52   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 35/59] KVM: arm/arm64: nv: Support multiple nested stage 2 mmu structures Marc Zyngier
2019-06-25 12:19   ` Alexandru Elisei
2019-07-03 13:47     ` Marc Zyngier
2019-06-27 13:15   ` Julien Thierry
2019-07-04 15:51   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 36/59] KVM: arm64: nv: Implement nested Stage-2 page table walk logic Marc Zyngier
2019-06-21  9:38 ` [PATCH 37/59] KVM: arm64: nv: Handle shadow stage 2 page faults Marc Zyngier
2019-07-05 14:28   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 38/59] KVM: arm64: nv: Unmap/flush shadow stage 2 page tables Marc Zyngier
2019-07-01  8:03   ` Julien Thierry
2019-06-21  9:38 ` [PATCH 39/59] KVM: arm64: nv: Move last_vcpu_ran to be per s2 mmu Marc Zyngier
2019-07-01  9:10   ` Julien Thierry
2019-07-05 15:28   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 40/59] KVM: arm64: nv: Don't always start an S2 MMU search from the beginning Marc Zyngier
2019-07-09  9:59   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 41/59] KVM: arm64: nv: Introduce sys_reg_desc.forward_trap Marc Zyngier
2019-06-21  9:38 ` [PATCH 42/59] KVM: arm64: nv: Rework the system instruction emulation framework Marc Zyngier
2019-06-21  9:38 ` Marc Zyngier [this message]
2019-07-01 15:45   ` [PATCH 43/59] KVM: arm64: nv: Trap and emulate AT instructions from virtual EL2 Julien Thierry
2019-07-09 13:20   ` Alexandru Elisei
2019-07-18 12:13     ` Tomasz Nowicki
2019-07-18 12:36       ` Alexandru Elisei
2019-07-18 12:56         ` Alexandru Elisei
2019-07-18 12:59         ` Tomasz Nowicki
2019-07-24 10:25   ` Tomasz Nowicki
2019-07-24 12:39     ` Marc Zyngier
2019-07-24 13:56       ` Tomasz Nowicki
2019-06-21  9:38 ` [PATCH 44/59] KVM: arm64: nv: Trap and emulate TLBI " Marc Zyngier
2019-07-02 12:37   ` Julien Thierry
2019-07-10 10:15   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 45/59] KVM: arm64: nv: Handle traps for timer _EL02 and _EL2 sysregs accessors Marc Zyngier
2019-06-21  9:38 ` [PATCH 46/59] KVM: arm64: nv: arch_timer: Support hyp timer emulation Marc Zyngier
2019-07-10 16:23   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 47/59] KVM: arm64: nv: Propagate CNTVOFF_EL2 to the virtual EL1 timer Marc Zyngier
2019-08-08  9:34   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 48/59] KVM: arm64: nv: Load timer before the GIC Marc Zyngier
2019-07-11 13:17   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 49/59] KVM: arm64: nv: vgic-v3: Take cpu_if pointer directly instead of vcpu Marc Zyngier
2019-06-21  9:38 ` [PATCH 50/59] KVM: arm64: nv: Nested GICv3 Support Marc Zyngier
2019-07-16 11:41   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 51/59] KVM: arm64: nv: vgic: Emulate the HW bit in software Marc Zyngier
2019-06-21  9:38 ` [PATCH 52/59] KVM: arm64: nv: vgic: Allow userland to set VGIC maintenance IRQ Marc Zyngier
2019-07-04  7:38   ` Julien Thierry
2019-07-04  9:01     ` Andre Przywara
2019-07-04  9:04       ` Julien Thierry
2019-06-21  9:38 ` [PATCH 53/59] KVM: arm64: nv: Implement maintenance interrupt forwarding Marc Zyngier
2019-07-04  8:06   ` Julien Thierry
2019-07-16 16:35   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 54/59] KVM: arm64: nv: Add nested GICv3 tracepoints Marc Zyngier
2019-06-21  9:38 ` [PATCH 55/59] arm64: KVM: nv: Add handling of EL2-specific timer registers Marc Zyngier
2019-07-11 12:35   ` Alexandru Elisei
2019-07-17 10:19   ` Alexandru Elisei
2019-06-21  9:38 ` [PATCH 56/59] arm64: KVM: nv: Honor SCTLR_EL2.SPAN on entering vEL2 Marc Zyngier
2019-06-21  9:38 ` [PATCH 57/59] arm64: KVM: nv: Handle SCTLR_EL2 RES0/RES1 bits Marc Zyngier
2019-06-21  9:38 ` [PATCH 58/59] arm64: KVM: nv: Restrict S2 RD/WR permissions to match the guest's Marc Zyngier
2019-06-21  9:38 ` [PATCH 59/59] arm64: KVM: nv: Allow userspace to request KVM_ARM_VCPU_NESTED_VIRT Marc Zyngier
2019-06-21  9:57 ` [PATCH 00/59] KVM: arm64: ARMv8.3 Nested Virtualization support Itaru Kitayama
2019-06-21 11:21   ` Marc Zyngier
2019-08-02 10:11 ` Alexandru Elisei
2019-08-02 10:30   ` Andrew Jones
2019-08-09 10:01   ` Alexandru Elisei
2019-08-09 11:44     ` Andrew Jones
2019-08-09 12:00       ` Alexandru Elisei
2019-08-09 13:00         ` Andrew Jones
2019-08-22 11:57     ` Alexandru Elisei
2019-08-22 15:32       ` Alexandru Elisei

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