Subject: [PATCH v7 4/6] KVM: PPC: Book3S HV: Nested support in H_RPT_INVALIDATE

From: Bharata B Rao <[email-masked]>
Date: Wed, 5 May 2021 21:16:40 +0530

Enable support for process-scoped invalidations from nested
guests and partition-scoped invalidations for nested guests.

Process-scoped invalidations for any level of nested guests
are handled by implementing H_RPT_INVALIDATE handler in the
nested guest exit path in L0.

Partition-scoped invalidation requests are forwarded to the
right nested guest, handled there and passed down to L0
for eventual handling.

Signed-off-by: Bharata B Rao <[email-masked]>
Signed-off-by: Aneesh Kumar K.V <[email-masked]>
	[Nested guest partition-scoped invalidation changes]
---
 .../include/asm/book3s/64/tlbflush-radix.h    |   4 +
 arch/powerpc/include/asm/kvm_book3s.h         |   3 +
 arch/powerpc/kvm/book3s_hv.c                  |  66 ++++++++++-
 arch/powerpc/kvm/book3s_hv_nested.c           | 104 ++++++++++++++++++
 arch/powerpc/mm/book3s64/radix_tlb.c          |   4 -
 5 files changed, 174 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
index 8b33601cdb9d..a46fd37ad552 100644
--- a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
+++ b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
@@ -4,6 +4,10 @@
 
 #include <asm/hvcall.h>
 
+#define RIC_FLUSH_TLB 0
+#define RIC_FLUSH_PWC 1
+#define RIC_FLUSH_ALL 2
+
 struct vm_area_struct;
 struct mm_struct;
 struct mmu_gather;
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index a6e9a5585e61..fdf54741c58c 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -307,6 +307,9 @@ void kvmhv_set_ptbl_entry(unsigned int lpid, u64 dw0, u64 dw1);
 void kvmhv_release_all_nested(struct kvm *kvm);
 long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu);
 long kvmhv_do_nested_tlbie(struct kvm_vcpu *vcpu);
+long do_h_rpt_invalidate_pat(struct kvm_vcpu *vcpu, unsigned long lpid,
+			     unsigned long type, unsigned long pg_sizes,
+			     unsigned long start, unsigned long end);
 int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu,
 			  u64 time_limit, unsigned long lpcr);
 void kvmhv_save_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr);
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index bcf34246bbe9..a2e7fbec796a 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -925,6 +925,41 @@ static int kvmppc_get_yield_count(struct kvm_vcpu *vcpu)
 	return yield_count;
 }
 
+/*
+ * H_RPT_INVALIDATE hcall handler for nested guests.
+ *
+ * Handles only nested process-scoped invalidation requests in L0.
+ */
+static int kvmppc_nested_h_rpt_invalidate(struct kvm_vcpu *vcpu)
+{
+	unsigned long type = kvmppc_get_gpr(vcpu, 6);
+	unsigned long pid, pg_sizes, start, end, psize;
+	struct mmu_psize_def *def;
+
+	/*
+	 * The partition-scoped invalidations aren't handled here in L0.
+	 */
+	if (type & H_RPTI_TYPE_NESTED)
+		return RESUME_HOST;
+
+	pid = kvmppc_get_gpr(vcpu, 4);
+	pg_sizes = kvmppc_get_gpr(vcpu, 7);
+	start = kvmppc_get_gpr(vcpu, 8);
+	end = kvmppc_get_gpr(vcpu, 9);
+
+	for (psize = 0; psize < MMU_PAGE_COUNT; psize++) {
+		def = &mmu_psize_defs[psize];
+		if (pg_sizes & def->h_rpt_pgsize)
+			do_h_rpt_invalidate_prt(pid,
+						vcpu->arch.nested->shadow_lpid,
+						type, (1UL << def->shift),
+						psize, start, end);
+	}
+
+	kvmppc_set_gpr(vcpu, 3, H_SUCCESS);
+	return RESUME_GUEST;
+}
+
 static long kvmppc_h_rpt_invalidate(struct kvm_vcpu *vcpu,
 				    unsigned long id, unsigned long target,
 				    unsigned long type, unsigned long pg_sizes,
@@ -941,10 +976,18 @@ static long kvmppc_h_rpt_invalidate(struct kvm_vcpu *vcpu,
 
 	/*
 	 * Partition-scoped invalidation for nested guests.
-	 * Not yet supported
 	 */
-	if (type & H_RPTI_TYPE_NESTED)
-		return H_P3;
+	if (type & H_RPTI_TYPE_NESTED) {
+		if (!nesting_enabled(vcpu->kvm))
+			return H_FUNCTION;
+
+		/* Support only cores as target */
+		if (target != H_RPTI_TARGET_CMMU)
+			return H_P2;
+
+		return do_h_rpt_invalidate_pat(vcpu, id, type, pg_sizes,
+					       start, end);
+	}
 
 	/*
 	 * Process-scoped invalidation for L1 guests.
@@ -1639,6 +1682,23 @@ static int kvmppc_handle_nested_exit(struct kvm_vcpu *vcpu)
 		if (!xics_on_xive())
 			kvmppc_xics_rm_complete(vcpu, 0);
 		break;
+	case BOOK3S_INTERRUPT_SYSCALL:
+	{
+		unsigned long req = kvmppc_get_gpr(vcpu, 3);
+
+		/*
+		 * The H_RPT_INVALIDATE hcalls issued by nested
+		 * guests for process-scoped invalidations when
+		 * GTSE=0, are handled here in L0.
+		 */
+		if (req == H_RPT_INVALIDATE) {
+			r = kvmppc_nested_h_rpt_invalidate(vcpu);
+			break;
+		}
+
+		r = RESUME_HOST;
+		break;
+	}
 	default:
 		r = RESUME_HOST;
 		break;
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 60724f674421..91f10290130d 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -1214,6 +1214,110 @@ long kvmhv_do_nested_tlbie(struct kvm_vcpu *vcpu)
 	return H_SUCCESS;
 }
 
+static long do_tlb_invalidate_nested_tlb(struct kvm_vcpu *vcpu,
+					 unsigned long lpid,
+					 unsigned long page_size,
+					 unsigned long ap,
+					 unsigned long start,
+					 unsigned long end)
+{
+	unsigned long addr = start;
+	int ret;
+
+	do {
+		ret = kvmhv_emulate_tlbie_tlb_addr(vcpu, lpid, ap,
+						   get_epn(addr));
+		if (ret)
+			return ret;
+		addr += page_size;
+	} while (addr < end);
+
+	return ret;
+}
+
+static long do_tlb_invalidate_nested_all(struct kvm_vcpu *vcpu,
+					 unsigned long lpid, unsigned long ric)
+{
+	struct kvm *kvm = vcpu->kvm;
+	struct kvm_nested_guest *gp;
+
+	gp = kvmhv_get_nested(kvm, lpid, false);
+	if (gp) {
+		kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
+		kvmhv_put_nested(gp);
+	}
+	return H_SUCCESS;
+}
+
+/*
+ * Performs partition-scoped invalidations for nested guests
+ * as part of H_RPT_INVALIDATE hcall.
+ */
+long do_h_rpt_invalidate_pat(struct kvm_vcpu *vcpu, unsigned long lpid,
+			     unsigned long type, unsigned long pg_sizes,
+			     unsigned long start, unsigned long end)
+{
+	struct kvm_nested_guest *gp;
+	long ret;
+	unsigned long psize, ap;
+
+	/*
+	 * If L2 lpid isn't valid, we need to return H_PARAMETER.
+	 *
+	 * However, nested KVM issues a L2 lpid flush call when creating
+	 * partition table entries for L2. This happens even before the
+	 * corresponding shadow lpid is created in HV which happens in
+	 * H_ENTER_NESTED call. Since we can't differentiate this case from
+	 * the invalid case, we ignore such flush requests and return success.
+	 */
+	gp = kvmhv_find_nested(vcpu->kvm, lpid);
+	if (!gp)
+		return H_SUCCESS;
+
+	/*
+	 * A flush all request can be handled by a full lpid flush only.
+	 */
+	if ((type & H_RPTI_TYPE_NESTED_ALL) == H_RPTI_TYPE_NESTED_ALL)
+		return do_tlb_invalidate_nested_all(vcpu, lpid, RIC_FLUSH_ALL);
+
+#if 0
+	/*
+	 * We don't need to handle a PWC flush like process table here,
+	 * because intermediate partition scoped table in nested guest doesn't
+	 * really have PWC. Only level we have PWC is in L0 and for nested
+	 * invalidate at L0 we always do kvm_flush_lpid() which does
+	 * radix__flush_all_lpid(). For range invalidate at any level, we
+	 * are not removing the higher level page tables and hence there is
+	 * no PWC invalidate needed.
+	 */
+	if (type & H_RPTI_TYPE_PWC) {
+		ret = do_tlb_invalidate_nested_all(vcpu, lpid, RIC_FLUSH_PWC);
+		if (ret)
+			return H_P4;
+	}
+#endif
+
+	if (start == 0 && end == -1)
+		return do_tlb_invalidate_nested_all(vcpu, lpid, RIC_FLUSH_TLB);
+
+	if (type & H_RPTI_TYPE_TLB) {
+		struct mmu_psize_def *def;
+
+		for (psize = 0; psize < MMU_PAGE_COUNT; psize++) {
+			def = &mmu_psize_defs[psize];
+			if (!(pg_sizes & def->h_rpt_pgsize))
+				continue;
+
+			ret = do_tlb_invalidate_nested_tlb(vcpu, lpid,
+							   (1UL << def->shift),
+							   ap, start, end);
+			if (ret)
+				return H_P4;
+		}
+	}
+	return H_SUCCESS;
+}
+
 /* Used to convert a nested guest real address to a L1 guest real address */
 static int kvmhv_translate_addr_nested(struct kvm_vcpu *vcpu,
 				       struct kvm_nested_guest *gp,
diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c
index 65aad9ce3557..613198c41006 100644
--- a/arch/powerpc/mm/book3s64/radix_tlb.c
+++ b/arch/powerpc/mm/book3s64/radix_tlb.c
@@ -20,10 +20,6 @@
 
 #include "internal.h"
 
-#define RIC_FLUSH_TLB 0
-#define RIC_FLUSH_PWC 1
-#define RIC_FLUSH_ALL 2
-
 /*
  * tlbiel instruction for radix, set invalidation
  * i.e., r=1 and is=01 or is=10 or is=11
-- 
2.26.2