diff mbox

[3.13.y.z,extended,stable] Patch "arm: KVM: fix possible misalignment of PGDs and bounce page" has been added to staging queue

Message ID 1402426908-6367-1-git-send-email-kamal@canonical.com
State New
Headers show

Commit Message

Kamal Mostafa June 10, 2014, 7:01 p.m. UTC 
This is a note to let you know that I have just added a patch titled

    arm: KVM: fix possible misalignment of PGDs and bounce page

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.3.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

From 7ec7f8484671f35afab30199993627d083c9a95b Mon Sep 17 00:00:00 2001
From: Mark Salter <msalter@redhat.com>
Date: Fri, 28 Mar 2014 14:25:19 +0000
Subject: arm: KVM: fix possible misalignment of PGDs and bounce page

commit 5d4e08c45a6cf8f1ab3c7fa375007635ac569165 upstream.

The kvm/mmu code shared by arm and arm64 uses kalloc() to allocate
a bounce page (if hypervisor init code crosses page boundary) and
hypervisor PGDs. The problem is that kalloc() does not guarantee
the proper alignment. In the case of the bounce page, the page sized
buffer allocated may also cross a page boundary negating the purpose
and leading to a hang during kvm initialization. Likewise the PGDs
allocated may not meet the minimum alignment requirements of the
underlying MMU. This patch uses __get_free_page() to guarantee the
worst case alignment needs of the bounce page and PGDs on both arm
and arm64.

Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 arch/arm/kvm/mmu.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

--
1.9.1
diff mbox

Patch

diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 5809069..d2370d4 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -42,6 +42,8 @@  static unsigned long hyp_idmap_start;
 static unsigned long hyp_idmap_end;
 static phys_addr_t hyp_idmap_vector;

+#define pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
+
 #define kvm_pmd_huge(_x)	(pmd_huge(_x) || pmd_trans_huge(_x))

 static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
@@ -199,14 +201,14 @@  void free_boot_hyp_pgd(void)
 	if (boot_hyp_pgd) {
 		unmap_range(NULL, boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
 		unmap_range(NULL, boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
-		kfree(boot_hyp_pgd);
+		free_pages((unsigned long)boot_hyp_pgd, pgd_order);
 		boot_hyp_pgd = NULL;
 	}

 	if (hyp_pgd)
 		unmap_range(NULL, hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);

-	kfree(init_bounce_page);
+	free_page((unsigned long)init_bounce_page);
 	init_bounce_page = NULL;

 	mutex_unlock(&kvm_hyp_pgd_mutex);
@@ -236,7 +238,7 @@  void free_hyp_pgds(void)
 		for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)
 			unmap_range(NULL, hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE);

-		kfree(hyp_pgd);
+		free_pages((unsigned long)hyp_pgd, pgd_order);
 		hyp_pgd = NULL;
 	}

@@ -928,7 +930,7 @@  int kvm_mmu_init(void)
 		size_t len = __hyp_idmap_text_end - __hyp_idmap_text_start;
 		phys_addr_t phys_base;

-		init_bounce_page = kmalloc(PAGE_SIZE, GFP_KERNEL);
+		init_bounce_page = (void *)__get_free_page(GFP_KERNEL);
 		if (!init_bounce_page) {
 			kvm_err("Couldn't allocate HYP init bounce page\n");
 			err = -ENOMEM;
@@ -954,8 +956,9 @@  int kvm_mmu_init(void)
 			 (unsigned long)phys_base);
 	}

-	hyp_pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL);
-	boot_hyp_pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL);
+	hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, pgd_order);
+	boot_hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, pgd_order);
+
 	if (!hyp_pgd || !boot_hyp_pgd) {
 		kvm_err("Hyp mode PGD not allocated\n");
 		err = -ENOMEM;