Hi Eric,
On 20/09/18 15:25, Auger Eric wrote:
Hi Suzuki,
On 9/17/18 12:41 PM, Suzuki K Poulose wrote:
VTCR_EL2 holds the following key stage2 translation table
parameters:
SL0 - Entry level in the page table lookup.
T0SZ - Denotes the size of the memory addressed by the table.
We have been using fixed values for the SL0 depending on the
page size as we have a fixed IPA size. But since we are about
to make it dynamic, we need to calculate the SL0 at runtime
per VM. This patch adds a helper to compute the value of SL0
for a VM based on the IPA size.
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: Christoffer Dall <cdall@xxxxxxxxxx>
Cc: Eric Auger <eric.auger@xxxxxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
---
Changes since v3:
- Update reference to latest ARM ARM.
- Update per-vm VTCR value of SL0.
- Add helpers to decode levels from SL0.
- Didn't pick up Reviewed-by tag from Eric, as there
are some new changes in this version
(-)
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 3fb1d440be6e..5c1487dc5dca 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -121,7 +121,6 @@
#define VTCR_EL2_IRGN0_WBWA TCR_IRGN0_WBWA
#define VTCR_EL2_SL0_SHIFT 6
#define VTCR_EL2_SL0_MASK (3 << VTCR_EL2_SL0_SHIFT)
-#define VTCR_EL2_SL0_LVL1 (1 << VTCR_EL2_SL0_SHIFT)
#define VTCR_EL2_T0SZ_MASK 0x3f
#define VTCR_EL2_VS_SHIFT 19
#define VTCR_EL2_VS_8BIT (0 << VTCR_EL2_VS_SHIFT)
@@ -148,29 +147,59 @@
/*
* Stage2 translation configuration:
* 64kB pages (TG0 = 1)
- * 2 level page tables (SL = 1)
*/
-#define VTCR_EL2_TGRAN_FLAGS (VTCR_EL2_TG0_64K | VTCR_EL2_SL0_LVL1)
-#define VTTBR_X_TGRAN_MAGIC 38
+#define VTCR_EL2_TGRAN VTCR_EL2_TG0_64K
+#define VTCR_EL2_TGRAN_SL0_BASE 3UL
the name if not obvious. I understand this is yet another magic number
used in the formulae below:
SL0(PAGE_SIZE, Entry_level) = SL0_BASE(PAGE_SIZE) - Entry_Level
I first tried to map this onto some spec fields. May be worth a comment?
Sure, I will make that clear.
Besides
Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx>
Thanks
Suzuki
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