[PATCH v9 5/8] KVM: PPC: Handle memory plug/unplug to secure VM

[Bharata B Rao <bharata@xxxxxxxxxxxxx>]

Register the new memslot with UV during plug and unregister
the memslot during unplug.

Signed-off-by: Bharata B Rao <bharata@xxxxxxxxxxxxx>
Acked-by: Paul Mackerras <paulus@xxxxxxxxxx>
Reviewed-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxx>
---
 arch/powerpc/include/asm/ultravisor-api.h |  1 +
 arch/powerpc/include/asm/ultravisor.h     |  5 +++++
 arch/powerpc/kvm/book3s_hv.c              | 21 +++++++++++++++++++++
 3 files changed, 27 insertions(+)

diff --git a/arch/powerpc/include/asm/ultravisor-api.h b/arch/powerpc/include/asm/ultravisor-api.h
index c578d9b13a56..46b1ee381695 100644
--- a/arch/powerpc/include/asm/ultravisor-api.h
+++ b/arch/powerpc/include/asm/ultravisor-api.h
@@ -26,6 +26,7 @@
 #define UV_WRITE_PATE			0xF104
 #define UV_RETURN			0xF11C
 #define UV_REGISTER_MEM_SLOT		0xF120
+#define UV_UNREGISTER_MEM_SLOT		0xF124
 #define UV_PAGE_IN			0xF128
 #define UV_PAGE_OUT			0xF12C
 
diff --git a/arch/powerpc/include/asm/ultravisor.h b/arch/powerpc/include/asm/ultravisor.h
index 58ccf5e2d6bb..719c0c3930b9 100644
--- a/arch/powerpc/include/asm/ultravisor.h
+++ b/arch/powerpc/include/asm/ultravisor.h
@@ -52,4 +52,9 @@ static inline int uv_register_mem_slot(u64 lpid, u64 start_gpa, u64 size,
 			    size, flags, slotid);
 }
 
+static inline int uv_unregister_mem_slot(u64 lpid, u64 slotid)
+{
+	return ucall_norets(UV_UNREGISTER_MEM_SLOT, lpid, slotid);
+}
+
 #endif	/* _ASM_POWERPC_ULTRAVISOR_H */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 3ba27fed3018..c5320cc0a534 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -74,6 +74,7 @@
 #include <asm/hw_breakpoint.h>
 #include <asm/kvm_host.h>
 #include <asm/kvm_book3s_uvmem.h>
+#include <asm/ultravisor.h>
 
 #include "book3s.h"
 
@@ -4517,6 +4518,26 @@ static void kvmppc_core_commit_memory_region_hv(struct kvm *kvm,
 	if (change == KVM_MR_FLAGS_ONLY && kvm_is_radix(kvm) &&
 	    ((new->flags ^ old->flags) & KVM_MEM_LOG_DIRTY_PAGES))
 		kvmppc_radix_flush_memslot(kvm, old);
+	/*
+	 * If UV hasn't yet called H_SVM_INIT_START, don't register memslots.
+	 */
+	if (!kvm->arch.secure_guest)
+		return;
+
+	switch (change) {
+	case KVM_MR_CREATE:
+		uv_register_mem_slot(kvm->arch.lpid,
+				     new->base_gfn << PAGE_SHIFT,
+				     new->npages * PAGE_SIZE,
+				     0, new->id);
+		break;
+	case KVM_MR_DELETE:
+		uv_unregister_mem_slot(kvm->arch.lpid, old->id);
+		break;
+	default:
+		/* TODO: Handle KVM_MR_MOVE */
+		break;
+	}
 }
 
 /*
-- 
2.21.0