Merge branch 'aarch64/kvm-bounce-page' into aarch64/for-next/core

Rework of the KVM HYP bounce page from Ard Biesheuvel. Subsequent arm64
idmap rework depends on this, so merge it here with Marc Zyngier's
blessing (kvm-arm co-maintainer).

1 files changed, 11 insertions, 6 deletions

diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index 5d9d2dca530d..a2c29865c3fe 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -23,10 +23,14 @@ jiffies = jiffies_64;
 
 #define HYPERVISOR_TEXT                                 \
         /*                                              \
-         * Force the alignment to be compatible with    \
-         * the vectors requirements                     \
+         * Align to 4 KB so that                        \
+         * a) the HYP vector table is at its minimum    \
+         *    alignment of 2048 bytes                   \
+         * b) the HYP init code will not cross a page   \
+         *    boundary if its size does not exceed      \
+         *    4 KB (see related ASSERT() below)         \
          */                                             \
-        . = ALIGN(2048);                                \
+        . = ALIGN(SZ_4K);                               \
         VMLINUX_SYMBOL(__hyp_idmap_text_start) = .;     \
         *(.hyp.idmap.text)                              \
         VMLINUX_SYMBOL(__hyp_idmap_text_end) = .;       \
@@ -163,10 +167,11 @@ SECTIONS
 }
 
 /*
- * The HYP init code can't be more than a page long.
+ * The HYP init code can't be more than a page long,
+ * and should not cross a page boundary.
  */
-ASSERT(((__hyp_idmap_text_start + PAGE_SIZE) > __hyp_idmap_text_end),
-       "HYP init code too big")
+ASSERT(__hyp_idmap_text_end - (__hyp_idmap_text_start & ~(SZ_4K - 1)) <= SZ_4K,
+        "HYP init code too big or misaligned")
 
 /*
  * If padding is applied before .head.text, virt<->phys conversions will fail.