[RFC PATCH 2/6] KVM: arm64: Add support for FEAT_TLBIRANGE

[Raghavendra Rao Ananta]

Define a generic function __kvm_tlb_flush_range() to
invalidate the TLBs over a range of addresses. Use
this to define  __kvm_tlb_flush_range_vmid_ipa()
(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 conviniently replace global TLBI such
as vmalls12e1is in the map, unmap, and dirty-logging
paths with ripas2e1is instead.

Signed-off-by: Raghavendra Rao Ananta <rananta at google.com>
---
 arch/arm64/include/asm/kvm_asm.h   | 21 +++++++++++++++++++++
 arch/arm64/kvm/hyp/nvhe/hyp-main.c | 11 +++++++++++
 arch/arm64/kvm/hyp/nvhe/tlb.c      | 24 ++++++++++++++++++++++++
 arch/arm64/kvm/hyp/vhe/tlb.c       | 20 ++++++++++++++++++++
 4 files changed, 76 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 43c3bc0f9544d..bdf94ae0333b0 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -79,6 +79,7 @@ enum __kvm_host_smccc_func {
 	__KVM_HOST_SMCCC_FUNC___pkvm_init_vm,
 	__KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu,
 	__KVM_HOST_SMCCC_FUNC___pkvm_teardown_vm,
+	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_range_vmid_ipa,
 };
 
 #define DECLARE_KVM_VHE_SYM(sym)	extern char sym[]
@@ -221,10 +222,30 @@ DECLARE_KVM_NVHE_SYM(__per_cpu_end);
 DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs);
 #define __bp_harden_hyp_vecs	CHOOSE_HYP_SYM(__bp_harden_hyp_vecs)
 
+#define __kvm_tlb_flush_range(op, mmu, start, end, tlb_level) do {		\
+	unsigned long pages, stride;						\
+										\
+	stride = PAGE_SIZE;							\
+	start = round_down(start, stride);					\
+	end = round_up(end, stride);						\
+	pages = (end - start) >> PAGE_SHIFT;					\
+										\
+	if ((!system_supports_tlb_range() &&					\
+	     (end - start) >= (MAX_TLBI_OPS * stride)) ||			\
+	    pages >= MAX_TLBI_RANGE_PAGES) {					\
+		__kvm_tlb_flush_vmid(mmu);					\
+		break;								\
+	}									\
+										\
+	__flush_tlb_range_op(op, start, pages, stride, 0, tlb_level, false);	\
+} while (0)
+
 extern void __kvm_flush_vm_context(void);
 extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu);
 extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
 				     int level);
+extern void __kvm_tlb_flush_range_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t start,
+						phys_addr_t end, int level);
 extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
 
 extern void __kvm_timer_set_cntvoff(u64 cntvoff);
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 728e01d4536b0..ac52d0fbb9719 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -116,6 +116,16 @@ static void handle___kvm_flush_vm_context(struct kvm_cpu_context *host_ctxt)
 	__kvm_flush_vm_context();
 }
 
+static void handle___kvm_tlb_flush_range_vmid_ipa(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(phys_addr_t, end, host_ctxt, 3);
+	DECLARE_REG(int, level, host_ctxt, 4);
+
+	__kvm_tlb_flush_range_vmid_ipa(kern_hyp_va(mmu), start, end, level);
+}
+
 static void handle___kvm_tlb_flush_vmid_ipa(struct kvm_cpu_context *host_ctxt)
 {
 	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
@@ -314,6 +324,7 @@ static const hcall_t host_hcall[] = {
 	HANDLE_FUNC(__kvm_adjust_pc),
 	HANDLE_FUNC(__kvm_vcpu_run),
 	HANDLE_FUNC(__kvm_flush_vm_context),
+	HANDLE_FUNC(__kvm_tlb_flush_range_vmid_ipa),
 	HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa),
 	HANDLE_FUNC(__kvm_tlb_flush_vmid),
 	HANDLE_FUNC(__kvm_flush_cpu_context),
diff --git a/arch/arm64/kvm/hyp/nvhe/tlb.c b/arch/arm64/kvm/hyp/nvhe/tlb.c
index d296d617f5896..292f5c4834d08 100644
--- a/arch/arm64/kvm/hyp/nvhe/tlb.c
+++ b/arch/arm64/kvm/hyp/nvhe/tlb.c
@@ -55,6 +55,30 @@ static void __tlb_switch_to_host(struct tlb_inv_context *cxt)
 	}
 }
 
+void __kvm_tlb_flush_range_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t start,
+					phys_addr_t end, int level)
+{
+	struct tlb_inv_context cxt;
+
+	dsb(ishst);
+
+	/* Switch to requested VMID */
+	__tlb_switch_to_guest(mmu, &cxt);
+
+	__kvm_tlb_flush_range(ipas2e1is, mmu, start, end, level);
+
+	dsb(ish);
+	__tlbi(vmalle1is);
+	dsb(ish);
+	isb();
+
+	/* See the comment below in __kvm_tlb_flush_vmid_ipa() */
+	if (icache_is_vpipt())
+		icache_inval_all_pou();
+
+	__tlb_switch_to_host(&cxt);
+}
+
 void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu,
 			      phys_addr_t ipa, int level)
 {
diff --git a/arch/arm64/kvm/hyp/vhe/tlb.c b/arch/arm64/kvm/hyp/vhe/tlb.c
index 24cef9b87f9e9..2631cc09e4184 100644
--- a/arch/arm64/kvm/hyp/vhe/tlb.c
+++ b/arch/arm64/kvm/hyp/vhe/tlb.c
@@ -79,6 +79,26 @@ static void __tlb_switch_to_host(struct tlb_inv_context *cxt)
 	local_irq_restore(cxt->flags);
 }
 
+void __kvm_tlb_flush_range_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t start,
+					phys_addr_t end, int level)
+{
+	struct tlb_inv_context cxt;
+
+	dsb(ishst);
+
+	/* Switch to requested VMID */
+	__tlb_switch_to_guest(mmu, &cxt);
+
+	__kvm_tlb_flush_range(ipas2e1is, mmu, start, end, level);
+
+	dsb(ish);
+	__tlbi(vmalle1is);
+	dsb(ish);
+	isb();
+
+	__tlb_switch_to_host(&cxt);
+}
+
 void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu,
 			      phys_addr_t ipa, int level)
 {
-- 
2.39.0.314.g84b9a713c41-goog