diff mbox series

[XEN,v3,9/9] xen/arm: p2m: Enable support for 32bit IPA

Message ID 20230208120529.22313-10-ayan.kumar.halder@amd.com (mailing list archive)
State Superseded
Headers show
Series Add support for 32 bit physical address | expand

Commit Message

Ayan Kumar Halder Feb. 8, 2023, 12:05 p.m. UTC 
VTCR.T0SZ should be set as 0x20 to support 32bit IPA.
Refer ARM DDI 0487I.a ID081822, G8-9824, G8.2.171, VTCR,
"Virtualization Translation Control Register" for the bit descriptions.

Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@amd.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
---
Changes from -

v1 - New patch.

v2 - 1. Added Ack.

 xen/arch/arm/p2m.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

Comments

Julien Grall Feb. 11, 2023, 10:21 a.m. UTC | #1 
Hi Ayan,

On 08/02/2023 12:05, Ayan Kumar Halder wrote:
> VTCR.T0SZ should be set as 0x20 to support 32bit IPA.
> Refer ARM DDI 0487I.a ID081822, G8-9824, G8.2.171, VTCR,
> "Virtualization Translation Control Register" for the bit descriptions.
> 
> Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@amd.com>
> Acked-by: Stefano Stabellini <sstabellini@kernel.org>

This will need a respin based on the discussion we had in v2. The main 
things are:
    - 32-bit IPA will be using one page at the root (not 2 like for 
40-bit IPA)
    - the code should be consolidate with arm64 as the logic is mainly 
the same.

Cheers,
diff mbox series

Patch

diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 948f199d84..cfdea55e71 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -2266,13 +2266,17 @@  void __init setup_virt_paging(void)
     register_t val = VTCR_RES1|VTCR_SH0_IS|VTCR_ORGN0_WBWA|VTCR_IRGN0_WBWA;
 
 #ifdef CONFIG_ARM_32
-    if ( p2m_ipa_bits < 40 )
+    if ( p2m_ipa_bits < PADDR_BITS )
         panic("P2M: Not able to support %u-bit IPA at the moment\n",
               p2m_ipa_bits);
 
-    printk("P2M: 40-bit IPA\n");
-    p2m_ipa_bits = 40;
+    printk("P2M: %u-bit IPA\n",PADDR_BITS);
+    p2m_ipa_bits = PADDR_BITS;
+#ifdef CONFIG_ARM_PA_32
+    val |= VTCR_T0SZ(0x20); /* 32 bit IPA */
+#else
     val |= VTCR_T0SZ(0x18); /* 40 bit IPA */
+#endif
     val |= VTCR_SL0(0x1); /* P2M starts at first level */
 #else /* CONFIG_ARM_64 */
     static const struct {