ARM: KVM: perform HYP initilization for hotplugged CPUs

Now that we have the necessary infrastructure to boot a hotplugged CPU
at any point in time, wire a CPU notifier that will perform the HYP
init for the incoming CPU.

Note that this depends on the platform code and/or firmware to boot the
incoming CPU with HYP mode enabled and return to the kernel by following
the normal boot path (HYP stub installed).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>

1 files changed, 28 insertions, 7 deletions

diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 4646c17f571..965706578f1 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -156,6 +156,31 @@ static void unmap_range(pgd_t *pgdp, unsigned long long start, u64 size)
 }
 
 /**
+ * free_boot_hyp_pgd - free HYP boot page tables
+ *
+ * Free the HYP boot page tables. The bounce page is also freed.
+ */
+void free_boot_hyp_pgd(void)
+{
+	mutex_lock(&kvm_hyp_pgd_mutex);
+
+	if (boot_hyp_pgd) {
+		unmap_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
+		unmap_range(boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
+		kfree(boot_hyp_pgd);
+		boot_hyp_pgd = NULL;
+	}
+
+	if (hyp_pgd)
+		unmap_range(hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
+
+	kfree(init_bounce_page);
+	init_bounce_page = NULL;
+
+	mutex_unlock(&kvm_hyp_pgd_mutex);
+}
+
+/**
  * free_hyp_pgds - free Hyp-mode page tables
  *
  * Assumes hyp_pgd is a page table used strictly in Hyp-mode and
@@ -169,13 +194,9 @@ void free_hyp_pgds(void)
 {
 	unsigned long addr;
 
-	mutex_lock(&kvm_hyp_pgd_mutex);
+	free_boot_hyp_pgd();
 
-	if (boot_hyp_pgd) {
-		unmap_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
-		unmap_range(boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
-		kfree(boot_hyp_pgd);
-	}
+	mutex_lock(&kvm_hyp_pgd_mutex);
 
 	if (hyp_pgd) {
 		for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE)
@@ -183,9 +204,9 @@ void free_hyp_pgds(void)
 		for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)
 			unmap_range(hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE);
 		kfree(hyp_pgd);
+		hyp_pgd = NULL;
 	}
 
-	kfree(init_bounce_page);
 	mutex_unlock(&kvm_hyp_pgd_mutex);
 }