2021-03-04 06:34:20

by Quentin Perret

Subject: [PATCH v3 30/32] KVM: arm64: Page-align the .hyp sections

We will soon unmap the .hyp sections from the host stage 2 in Protected
nVHE mode, which obvisouly works with at least page granularity, so make
sure to align them correctly.

Signed-off-by: Quentin Perret <[email protected]>
---
arch/arm64/kernel/vmlinux.lds.S | 22 +++++++++-------------
1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index e96173ce211b..709d2c433c5e 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -15,9 +15,11 @@

#define HYPERVISOR_DATA_SECTIONS \
HYP_SECTION_NAME(.rodata) : { \
+ . = ALIGN(PAGE_SIZE); \
__hyp_rodata_start = .; \
*(HYP_SECTION_NAME(.data..ro_after_init)) \
*(HYP_SECTION_NAME(.rodata)) \
+ . = ALIGN(PAGE_SIZE); \
__hyp_rodata_end = .; \
}

@@ -72,21 +74,14 @@ ENTRY(_text)
jiffies = jiffies_64;

#define HYPERVISOR_TEXT \
- /* \
- * 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(SZ_4K); \
+ . = ALIGN(PAGE_SIZE); \
__hyp_idmap_text_start = .; \
*(.hyp.idmap.text) \
__hyp_idmap_text_end = .; \
__hyp_text_start = .; \
*(.hyp.text) \
HYPERVISOR_EXTABLE \
+ . = ALIGN(PAGE_SIZE); \
__hyp_text_end = .;

#define IDMAP_TEXT \
@@ -322,11 +317,12 @@ SECTIONS
#include "image-vars.h"

/*
- * The HYP init code and ID map text can't be longer than a page each,
- * and should not cross a page boundary.
+ * The HYP init code and ID map text can't be longer than a page each. The
+ * former is page-aligned, but the latter may not be with 16K or 64K pages, so
+ * it should also not cross a page boundary.
*/
-ASSERT(__hyp_idmap_text_end - (__hyp_idmap_text_start & ~(SZ_4K - 1)) <= SZ_4K,
- "HYP init code too big or misaligned")
+ASSERT(__hyp_idmap_text_end - __hyp_idmap_text_start <= PAGE_SIZE,
+ "HYP init code too big")
ASSERT(__idmap_text_end - (__idmap_text_start & ~(SZ_4K - 1)) <= SZ_4K,
"ID map text too big or misaligned")
#ifdef CONFIG_HIBERNATION
--
2.30.1.766.gb4fecdf3b7-goog

2021-03-04 20:09:29

by Will Deacon

Subject: Re: [PATCH v3 30/32] KVM: arm64: Page-align the .hyp sections

On Tue, Mar 02, 2021 at 03:00:00PM +0000, Quentin Perret wrote:
> We will soon unmap the .hyp sections from the host stage 2 in Protected
> nVHE mode, which obvisouly works with at least page granularity, so make
> sure to align them correctly.

s/obvisouly/obviously/

>
> Signed-off-by: Quentin Perret <[email protected]>
> ---
> arch/arm64/kernel/vmlinux.lds.S | 22 +++++++++-------------
> 1 file changed, 9 insertions(+), 13 deletions(-)

With the typo fixed:

Acked-by: Will Deacon <[email protected]>

Will