KVM: arm64: Implement __kvm_tlb_flush_vmid_range()

Define  __kvm_tlb_flush_vmid_range() (for VHE and nVHE)
to flush a range of stage-2 page-tables using IPA in one go.
If the system supports FEAT_TLBIRANGE, the following patches
would conveniently replace global TLBI such as vmalls12e1is
in the map, unmap, and dirty-logging paths with ripas2e1is
instead.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230811045127.3308641-10-rananta@google.com

Author: rananta468

arch/arm64/include/asm/kvm_asm.h

@@ -70,6 +70,7 @@ enum __kvm_host_smccc_func {
 	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa,
 	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa_nsh,
 	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid,
+	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_range,
 	__KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context,
 	__KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff,
 	__KVM_HOST_SMCCC_FUNC___vgic_v3_read_vmcr,
@@ -229,6 +230,8 @@ extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
 extern void __kvm_tlb_flush_vmid_ipa_nsh(struct kvm_s2_mmu *mmu,
 					 phys_addr_t ipa,
 					 int level);
+extern void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
+					phys_addr_t start, unsigned long pages);
 extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
 
 extern void __kvm_timer_set_cntvoff(u64 cntvoff);

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

@@ -135,6 +135,16 @@ static void handle___kvm_tlb_flush_vmid_ipa_nsh(struct kvm_cpu_context *host_ctx
 	__kvm_tlb_flush_vmid_ipa_nsh(kern_hyp_va(mmu), ipa, level);
 }
 
+static void
+handle___kvm_tlb_flush_vmid_range(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
+	DECLARE_REG(phys_addr_t, start, host_ctxt, 2);
+	DECLARE_REG(unsigned long, pages, host_ctxt, 3);
+
+	__kvm_tlb_flush_vmid_range(kern_hyp_va(mmu), start, pages);
+}
+
 static void handle___kvm_tlb_flush_vmid(struct kvm_cpu_context *host_ctxt)
 {
 	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
@@ -327,6 +337,7 @@ static const hcall_t host_hcall[] = {
 	HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa),
 	HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa_nsh),
 	HANDLE_FUNC(__kvm_tlb_flush_vmid),
+	HANDLE_FUNC(__kvm_tlb_flush_vmid_range),
 	HANDLE_FUNC(__kvm_flush_cpu_context),
 	HANDLE_FUNC(__kvm_timer_set_cntvoff),
 	HANDLE_FUNC(__vgic_v3_read_vmcr),

arch/arm64/kvm/hyp/nvhe/tlb.c

@@ -182,6 +182,36 @@ void __kvm_tlb_flush_vmid_ipa_nsh(struct kvm_s2_mmu *mmu,
 	__tlb_switch_to_host(&cxt);
 }
 
+void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
+				phys_addr_t start, unsigned long pages)
+{
+	struct tlb_inv_context cxt;
+	unsigned long stride;
+
+	/*
+	 * Since the range of addresses may not be mapped at
+	 * the same level, assume the worst case as PAGE_SIZE
+	 */
+	stride = PAGE_SIZE;
+	start = round_down(start, stride);
+
+	/* Switch to requested VMID */
+	__tlb_switch_to_guest(mmu, &cxt, false);
+
+	__flush_s2_tlb_range_op(ipas2e1is, start, pages, stride, 0);
+
+	dsb(ish);
+	__tlbi(vmalle1is);
+	dsb(ish);
+	isb();
+
+	/* See the comment in __kvm_tlb_flush_vmid_ipa() */
+	if (icache_is_vpipt())
+		icache_inval_all_pou();
+
+	__tlb_switch_to_host(&cxt);
+}
+
 void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu)
 {
 	struct tlb_inv_context cxt;

arch/arm64/kvm/hyp/vhe/tlb.c

@@ -143,6 +143,34 @@ void __kvm_tlb_flush_vmid_ipa_nsh(struct kvm_s2_mmu *mmu,
 	__tlb_switch_to_host(&cxt);
 }
 
+void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
+				phys_addr_t start, unsigned long pages)
+{
+	struct tlb_inv_context cxt;
+	unsigned long stride;
+
+	/*
+	 * Since the range of addresses may not be mapped at
+	 * the same level, assume the worst case as PAGE_SIZE
+	 */
+	stride = PAGE_SIZE;
+	start = round_down(start, stride);
+
+	dsb(ishst);
+
+	/* Switch to requested VMID */
+	__tlb_switch_to_guest(mmu, &cxt);
+
+	__flush_s2_tlb_range_op(ipas2e1is, start, pages, stride, 0);
+
+	dsb(ish);
+	__tlbi(vmalle1is);
+	dsb(ish);
+	isb();
+
+	__tlb_switch_to_host(&cxt);
+}
+
 void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu)
 {
 	struct tlb_inv_context cxt;