Merge branch 'kvm-arm64/host-hvc-table' into kvmarm-master/next

Signed-off-by: Marc Zyngier <maz@kernel.org>

arch/arm64/include/asm/kvm_asm.h

@@ -189,8 +189,6 @@ extern void __kvm_timer_set_cntvoff(u64 cntvoff);
 
 extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
 
-extern void __kvm_enable_ssbs(void);
-
 extern u64 __vgic_v3_get_ich_vtr_el2(void);
 extern u64 __vgic_v3_read_vmcr(void);
 extern void __vgic_v3_write_vmcr(u32 vmcr);

arch/arm64/include/asm/kvm_mmu.h

@@ -72,6 +72,28 @@ alternative_cb kvm_update_va_mask
 alternative_cb_end
 .endm
 
+/*
+ * Convert a kernel image address to a PA
+ * reg: kernel address to be converted in place
+ * tmp: temporary register
+ *
+ * The actual code generation takes place in kvm_get_kimage_voffset, and
+ * the instructions below are only there to reserve the space and
+ * perform the register allocation (kvm_get_kimage_voffset uses the
+ * specific registers encoded in the instructions).
+ */
+.macro kimg_pa reg, tmp
+alternative_cb kvm_get_kimage_voffset
+	movz	\tmp, #0
+	movk	\tmp, #0, lsl #16
+	movk	\tmp, #0, lsl #32
+	movk	\tmp, #0, lsl #48
+alternative_cb_end
+
+	/* reg = __pa(reg) */
+	sub	\reg, \reg, \tmp
+.endm
+
 #else
 
 #include <linux/pgtable.h>
@@ -98,6 +120,24 @@ static __always_inline unsigned long __kern_hyp_va(unsigned long v)
 
 #define kern_hyp_va(v) 	((typeof(v))(__kern_hyp_va((unsigned long)(v))))
 
+static __always_inline unsigned long __kimg_hyp_va(unsigned long v)
+{
+	unsigned long offset;
+
+	asm volatile(ALTERNATIVE_CB("movz %0, #0\n"
+				    "movk %0, #0, lsl #16\n"
+				    "movk %0, #0, lsl #32\n"
+				    "movk %0, #0, lsl #48\n",
+				    kvm_update_kimg_phys_offset)
+		     : "=r" (offset));
+
+	return __kern_hyp_va((v - offset) | PAGE_OFFSET);
+}
+
+#define kimg_fn_hyp_va(v) 	((typeof(*v))(__kimg_hyp_va((unsigned long)(v))))
+
+#define kimg_fn_ptr(x)	(typeof(x) **)(x)
+
 /*
  * We currently support using a VM-specified IPA size. For backward
  * compatibility, the default IPA size is fixed to 40bits.

arch/arm64/include/asm/sysreg.h

@@ -465,6 +465,7 @@
 
 #define SYS_PMCCFILTR_EL0		sys_reg(3, 3, 14, 15, 7)
 
+#define SYS_SCTLR_EL2			sys_reg(3, 4, 1, 0, 0)
 #define SYS_ZCR_EL2			sys_reg(3, 4, 1, 2, 0)
 #define SYS_DACR32_EL2			sys_reg(3, 4, 3, 0, 0)
 #define SYS_SPSR_EL2			sys_reg(3, 4, 4, 0, 0)

arch/arm64/kernel/image-vars.h

@@ -64,13 +64,12 @@ __efistub__ctype		= _ctype;
 /* Alternative callbacks for init-time patching of nVHE hyp code. */
 KVM_NVHE_ALIAS(kvm_patch_vector_branch);
 KVM_NVHE_ALIAS(kvm_update_va_mask);
+KVM_NVHE_ALIAS(kvm_update_kimg_phys_offset);
+KVM_NVHE_ALIAS(kvm_get_kimage_voffset);
 
 /* Global kernel state accessed by nVHE hyp code. */
 KVM_NVHE_ALIAS(kvm_vgic_global_state);
 
-/* Kernel constant needed to compute idmap addresses. */
-KVM_NVHE_ALIAS(kimage_voffset);
-
 /* Kernel symbols used to call panic() from nVHE hyp code (via ERET). */
 KVM_NVHE_ALIAS(__hyp_panic_string);
 KVM_NVHE_ALIAS(panic);

arch/arm64/kvm/hyp/nvhe/host.S

@@ -13,8 +13,6 @@
 	.text
 
 SYM_FUNC_START(__host_exit)
-	stp	x0, x1, [sp, #-16]!
-
 	get_host_ctxt	x0, x1
 
 	/* Store the host regs x2 and x3 */
@@ -99,13 +97,15 @@ SYM_FUNC_END(__hyp_do_panic)
 	mrs	x0, esr_el2
 	lsr	x0, x0, #ESR_ELx_EC_SHIFT
 	cmp	x0, #ESR_ELx_EC_HVC64
-	ldp	x0, x1, [sp], #16
 	b.ne	__host_exit
 
+	ldp	x0, x1, [sp]		// Don't fixup the stack yet
+
 	/* Check for a stub HVC call */
 	cmp	x0, #HVC_STUB_HCALL_NR
 	b.hs	__host_exit
 
+	add	sp, sp, #16
 	/*
 	 * Compute the idmap address of __kvm_handle_stub_hvc and
 	 * jump there. Since we use kimage_voffset, do not use the
@@ -115,10 +115,7 @@ SYM_FUNC_END(__hyp_do_panic)
 	 * Preserve x0-x4, which may contain stub parameters.
 	 */
 	ldr	x5, =__kvm_handle_stub_hvc
-	ldr_l	x6, kimage_voffset
-
-	/* x5 = __pa(x5) */
-	sub	x5, x5, x6
+	kimg_pa x5, x6
 	br	x5
 .L__vect_end\@:
 .if ((.L__vect_end\@ - .L__vect_start\@) > 0x80)

arch/arm64/kvm/hyp/nvhe/hyp-main.c

@@ -12,106 +12,150 @@
 #include <asm/kvm_hyp.h>
 #include <asm/kvm_mmu.h>
 
-#include <kvm/arm_hypercalls.h>
-
-static void handle_host_hcall(unsigned long func_id,
-			      struct kvm_cpu_context *host_ctxt)
-{
-	unsigned long ret = 0;
-
-	switch (func_id) {
-	case KVM_HOST_SMCCC_FUNC(__kvm_vcpu_run): {
-		unsigned long r1 = host_ctxt->regs.regs[1];
-		struct kvm_vcpu *vcpu = (struct kvm_vcpu *)r1;
-
-		ret = __kvm_vcpu_run(kern_hyp_va(vcpu));
-		break;
-	}
-	case KVM_HOST_SMCCC_FUNC(__kvm_flush_vm_context):
-		__kvm_flush_vm_context();
-		break;
-	case KVM_HOST_SMCCC_FUNC(__kvm_tlb_flush_vmid_ipa): {
-		unsigned long r1 = host_ctxt->regs.regs[1];
-		struct kvm_s2_mmu *mmu = (struct kvm_s2_mmu *)r1;
-		phys_addr_t ipa = host_ctxt->regs.regs[2];
-		int level = host_ctxt->regs.regs[3];
-
-		__kvm_tlb_flush_vmid_ipa(kern_hyp_va(mmu), ipa, level);
-		break;
-	}
-	case KVM_HOST_SMCCC_FUNC(__kvm_tlb_flush_vmid): {
-		unsigned long r1 = host_ctxt->regs.regs[1];
-		struct kvm_s2_mmu *mmu = (struct kvm_s2_mmu *)r1;
-
-		__kvm_tlb_flush_vmid(kern_hyp_va(mmu));
-		break;
-	}
-	case KVM_HOST_SMCCC_FUNC(__kvm_tlb_flush_local_vmid): {
-		unsigned long r1 = host_ctxt->regs.regs[1];
-		struct kvm_s2_mmu *mmu = (struct kvm_s2_mmu *)r1;
-
-		__kvm_tlb_flush_local_vmid(kern_hyp_va(mmu));
-		break;
-	}
-	case KVM_HOST_SMCCC_FUNC(__kvm_timer_set_cntvoff): {
-		u64 cntvoff = host_ctxt->regs.regs[1];
-
-		__kvm_timer_set_cntvoff(cntvoff);
-		break;
-	}
-	case KVM_HOST_SMCCC_FUNC(__kvm_enable_ssbs):
-		__kvm_enable_ssbs();
-		break;
-	case KVM_HOST_SMCCC_FUNC(__vgic_v3_get_ich_vtr_el2):
-		ret = __vgic_v3_get_ich_vtr_el2();
-		break;
-	case KVM_HOST_SMCCC_FUNC(__vgic_v3_read_vmcr):
-		ret = __vgic_v3_read_vmcr();
-		break;
-	case KVM_HOST_SMCCC_FUNC(__vgic_v3_write_vmcr): {
-		u32 vmcr = host_ctxt->regs.regs[1];
-
-		__vgic_v3_write_vmcr(vmcr);
-		break;
-	}
-	case KVM_HOST_SMCCC_FUNC(__vgic_v3_init_lrs):
-		__vgic_v3_init_lrs();
-		break;
-	case KVM_HOST_SMCCC_FUNC(__kvm_get_mdcr_el2):
-		ret = __kvm_get_mdcr_el2();
-		break;
-	case KVM_HOST_SMCCC_FUNC(__vgic_v3_save_aprs): {
-		unsigned long r1 = host_ctxt->regs.regs[1];
-		struct vgic_v3_cpu_if *cpu_if = (struct vgic_v3_cpu_if *)r1;
-
-		__vgic_v3_save_aprs(kern_hyp_va(cpu_if));
-		break;
-	}
-	case KVM_HOST_SMCCC_FUNC(__vgic_v3_restore_aprs): {
-		unsigned long r1 = host_ctxt->regs.regs[1];
-		struct vgic_v3_cpu_if *cpu_if = (struct vgic_v3_cpu_if *)r1;
-
-		__vgic_v3_restore_aprs(kern_hyp_va(cpu_if));
-		break;
-	}
-	default:
-		/* Invalid host HVC. */
-		host_ctxt->regs.regs[0] = SMCCC_RET_NOT_SUPPORTED;
-		return;
-	}
-
-	host_ctxt->regs.regs[0] = SMCCC_RET_SUCCESS;
-	host_ctxt->regs.regs[1] = ret;
+#define cpu_reg(ctxt, r)	(ctxt)->regs.regs[r]
+#define DECLARE_REG(type, name, ctxt, reg)	\
+				type name = (type)cpu_reg(ctxt, (reg))
+
+static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1);
+
+	cpu_reg(host_ctxt, 1) =  __kvm_vcpu_run(kern_hyp_va(vcpu));
+}
+
+static void handle___kvm_flush_vm_context(struct kvm_cpu_context *host_ctxt)
+{
+	__kvm_flush_vm_context();
+}
+
+static void handle___kvm_tlb_flush_vmid_ipa(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
+	DECLARE_REG(phys_addr_t, ipa, host_ctxt, 2);
+	DECLARE_REG(int, level, host_ctxt, 3);
+
+	__kvm_tlb_flush_vmid_ipa(kern_hyp_va(mmu), ipa, level);
+}
+
+static void handle___kvm_tlb_flush_vmid(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
+
+	__kvm_tlb_flush_vmid(kern_hyp_va(mmu));
+}
+
+static void handle___kvm_tlb_flush_local_vmid(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
+
+	__kvm_tlb_flush_local_vmid(kern_hyp_va(mmu));
+}
+
+static void handle___kvm_timer_set_cntvoff(struct kvm_cpu_context *host_ctxt)
+{
+	__kvm_timer_set_cntvoff(cpu_reg(host_ctxt, 1));
+}
+
+static void handle___kvm_enable_ssbs(struct kvm_cpu_context *host_ctxt)
+{
+	u64 tmp;
+
+	tmp = read_sysreg_el2(SYS_SCTLR);
+	tmp |= SCTLR_ELx_DSSBS;
+	write_sysreg_el2(tmp, SYS_SCTLR);
+}
+
+static void handle___vgic_v3_get_ich_vtr_el2(struct kvm_cpu_context *host_ctxt)
+{
+	cpu_reg(host_ctxt, 1) = __vgic_v3_get_ich_vtr_el2();
+}
+
+static void handle___vgic_v3_read_vmcr(struct kvm_cpu_context *host_ctxt)
+{
+	cpu_reg(host_ctxt, 1) = __vgic_v3_read_vmcr();
+}
+
+static void handle___vgic_v3_write_vmcr(struct kvm_cpu_context *host_ctxt)
+{
+	__vgic_v3_write_vmcr(cpu_reg(host_ctxt, 1));
+}
+
+static void handle___vgic_v3_init_lrs(struct kvm_cpu_context *host_ctxt)
+{
+	__vgic_v3_init_lrs();
+}
+
+static void handle___kvm_get_mdcr_el2(struct kvm_cpu_context *host_ctxt)
+{
+	cpu_reg(host_ctxt, 1) = __kvm_get_mdcr_el2();
+}
+
+static void handle___vgic_v3_save_aprs(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(struct vgic_v3_cpu_if *, cpu_if, host_ctxt, 1);
+
+	__vgic_v3_save_aprs(kern_hyp_va(cpu_if));
+}
+
+static void handle___vgic_v3_restore_aprs(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(struct vgic_v3_cpu_if *, cpu_if, host_ctxt, 1);
+
+	__vgic_v3_restore_aprs(kern_hyp_va(cpu_if));
+}
+
+typedef void (*hcall_t)(struct kvm_cpu_context *);
+
+#define HANDLE_FUNC(x)	[__KVM_HOST_SMCCC_FUNC_##x] = kimg_fn_ptr(handle_##x)
+
+static const hcall_t *host_hcall[] = {
+	HANDLE_FUNC(__kvm_vcpu_run),
+	HANDLE_FUNC(__kvm_flush_vm_context),
+	HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa),
+	HANDLE_FUNC(__kvm_tlb_flush_vmid),
+	HANDLE_FUNC(__kvm_tlb_flush_local_vmid),
+	HANDLE_FUNC(__kvm_timer_set_cntvoff),
+	HANDLE_FUNC(__kvm_enable_ssbs),
+	HANDLE_FUNC(__vgic_v3_get_ich_vtr_el2),
+	HANDLE_FUNC(__vgic_v3_read_vmcr),
+	HANDLE_FUNC(__vgic_v3_write_vmcr),
+	HANDLE_FUNC(__vgic_v3_init_lrs),
+	HANDLE_FUNC(__kvm_get_mdcr_el2),
+	HANDLE_FUNC(__vgic_v3_save_aprs),
+	HANDLE_FUNC(__vgic_v3_restore_aprs),
+};
+
+static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(unsigned long, id, host_ctxt, 0);
+	const hcall_t *kfn;
+	hcall_t hfn;
+
+	id -= KVM_HOST_SMCCC_ID(0);
+
+	if (unlikely(id >= ARRAY_SIZE(host_hcall)))
+		goto inval;
+
+	kfn = host_hcall[id];
+	if (unlikely(!kfn))
+		goto inval;
+
+	cpu_reg(host_ctxt, 0) = SMCCC_RET_SUCCESS;
+
+	hfn = kimg_fn_hyp_va(kfn);
+	hfn(host_ctxt);
+
+	return;
+inval:
+	cpu_reg(host_ctxt, 0) = SMCCC_RET_NOT_SUPPORTED;
 }
 
 void handle_trap(struct kvm_cpu_context *host_ctxt)
 {
 	u64 esr = read_sysreg_el2(SYS_ESR);
-	unsigned long func_id;
 
-	if (ESR_ELx_EC(esr) != ESR_ELx_EC_HVC64)
+	if (unlikely(ESR_ELx_EC(esr) != ESR_ELx_EC_HVC64))
 		hyp_panic();
 
-	func_id = host_ctxt->regs.regs[0];
-	handle_host_hcall(func_id, host_ctxt);
+	handle_host_hcall(host_ctxt);
 }

arch/arm64/kvm/hyp/nvhe/sysreg-sr.c

@@ -33,14 +33,3 @@ void __sysreg_restore_state_nvhe(struct kvm_cpu_context *ctxt)
 	__sysreg_restore_user_state(ctxt);
 	__sysreg_restore_el2_return_state(ctxt);
 }
-
-void __kvm_enable_ssbs(void)
-{
-	u64 tmp;
-
-	asm volatile(
-	"mrs	%0, sctlr_el2\n"
-	"orr	%0, %0, %1\n"
-	"msr	sctlr_el2, %0"
-	: "=&r" (tmp) : "L" (SCTLR_ELx_DSSBS));
-}

arch/arm64/kvm/va_layout.c

@@ -11,6 +11,7 @@
 #include <asm/debug-monitors.h>
 #include <asm/insn.h>
 #include <asm/kvm_mmu.h>
+#include <asm/memory.h>
 
 /*
  * The LSB of the HYP VA tag
@@ -201,3 +202,58 @@ void kvm_patch_vector_branch(struct alt_instr *alt,
 					   AARCH64_INSN_BRANCH_NOLINK);
 	*updptr++ = cpu_to_le32(insn);
 }
+
+static void generate_mov_q(u64 val, __le32 *origptr, __le32 *updptr, int nr_inst)
+{
+	u32 insn, oinsn, rd;
+
+	BUG_ON(nr_inst != 4);
+
+	/* Compute target register */
+	oinsn = le32_to_cpu(*origptr);
+	rd = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RD, oinsn);
+
+	/* movz rd, #(val & 0xffff) */
+	insn = aarch64_insn_gen_movewide(rd,
+					 (u16)val,
+					 0,
+					 AARCH64_INSN_VARIANT_64BIT,
+					 AARCH64_INSN_MOVEWIDE_ZERO);
+	*updptr++ = cpu_to_le32(insn);
+
+	/* movk rd, #((val >> 16) & 0xffff), lsl #16 */
+	insn = aarch64_insn_gen_movewide(rd,
+					 (u16)(val >> 16),
+					 16,
+					 AARCH64_INSN_VARIANT_64BIT,
+					 AARCH64_INSN_MOVEWIDE_KEEP);
+	*updptr++ = cpu_to_le32(insn);
+
+	/* movk rd, #((val >> 32) & 0xffff), lsl #32 */
+	insn = aarch64_insn_gen_movewide(rd,
+					 (u16)(val >> 32),
+					 32,
+					 AARCH64_INSN_VARIANT_64BIT,
+					 AARCH64_INSN_MOVEWIDE_KEEP);
+	*updptr++ = cpu_to_le32(insn);
+
+	/* movk rd, #((val >> 48) & 0xffff), lsl #48 */
+	insn = aarch64_insn_gen_movewide(rd,
+					 (u16)(val >> 48),
+					 48,
+					 AARCH64_INSN_VARIANT_64BIT,
+					 AARCH64_INSN_MOVEWIDE_KEEP);
+	*updptr++ = cpu_to_le32(insn);
+}
+
+void kvm_update_kimg_phys_offset(struct alt_instr *alt,
+				 __le32 *origptr, __le32 *updptr, int nr_inst)
+{
+	generate_mov_q(kimage_voffset + PHYS_OFFSET, origptr, updptr, nr_inst);
+}
+
+void kvm_get_kimage_voffset(struct alt_instr *alt,
+			    __le32 *origptr, __le32 *updptr, int nr_inst)
+{
+	generate_mov_q(kimage_voffset, origptr, updptr, nr_inst);
+}