arm/arm64: KVM: Fix hyp mappings of vmalloc regions

[Linux-MTD Mailing List]

Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=40c2729bab48e2832b17c1fa8af9db60e776131b
Commit:     40c2729bab48e2832b17c1fa8af9db60e776131b
Parent:     5e01dc7b26d9f24f39abace5da98ccbd6a5ceb52
Author:     Christoffer Dall <christoffer.dall at linaro.org>
AuthorDate: Fri Nov 15 13:14:12 2013 -0800
Committer:  Christoffer Dall <christoffer.dall at linaro.org>
CommitDate: Sat Nov 16 18:54:45 2013 -0800

    arm/arm64: KVM: Fix hyp mappings of vmalloc regions
    
    Using virt_to_phys on percpu mappings is horribly wrong as it may be
    backed by vmalloc.  Introduce kvm_kaddr_to_phys which translates both
    types of valid kernel addresses to the corresponding physical address.
    
    At the same time resolves a typing issue where we were storing the
    physical address as a 32 bit unsigned long (on arm), truncating the
    physical address for addresses above the 4GB limit.  This caused
    breakage on Keystone.
    
    Cc: <stable at vger.kernel.org>	[3.10+]
    Reported-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
    Tested-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
    Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
    Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
---
 arch/arm/kvm/mmu.c | 34 ++++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index b0de86b..cb79a5d 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -307,6 +307,17 @@ out:
 	return err;
 }
 
+static phys_addr_t kvm_kaddr_to_phys(void *kaddr)
+{
+	if (!is_vmalloc_addr(kaddr)) {
+		BUG_ON(!virt_addr_valid(kaddr));
+		return __pa(kaddr);
+	} else {
+		return page_to_phys(vmalloc_to_page(kaddr)) +
+		       offset_in_page(kaddr);
+	}
+}
+
 /**
  * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode
  * @from:	The virtual kernel start address of the range
@@ -318,16 +329,27 @@ out:
  */
 int create_hyp_mappings(void *from, void *to)
 {
-	unsigned long phys_addr = virt_to_phys(from);
+	phys_addr_t phys_addr;
+	unsigned long virt_addr;
 	unsigned long start = KERN_TO_HYP((unsigned long)from);
 	unsigned long end = KERN_TO_HYP((unsigned long)to);
 
-	/* Check for a valid kernel memory mapping */
-	if (!virt_addr_valid(from) || !virt_addr_valid(to - 1))
-		return -EINVAL;
+	start = start & PAGE_MASK;
+	end = PAGE_ALIGN(end);
 
-	return __create_hyp_mappings(hyp_pgd, start, end,
-				     __phys_to_pfn(phys_addr), PAGE_HYP);
+	for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) {
+		int err;
+
+		phys_addr = kvm_kaddr_to_phys(from + virt_addr - start);
+		err = __create_hyp_mappings(hyp_pgd, virt_addr,
+					    virt_addr + PAGE_SIZE,
+					    __phys_to_pfn(phys_addr),
+					    PAGE_HYP);
+		if (err)
+			return err;
+	}
+
+	return 0;
 }
 
 /**