Skip to content

Commit

Permalink
KVM: ARM: fix the size of TTBCR_{T0SZ,T1SZ} masks
Browse files Browse the repository at this point in the history
The T{0,1}SZ fields of TTBCR are 3 bits wide when using the long descriptor
format. Likewise, the T0SZ field of the HTCR is 3-bits. KVM currently
defines TTBCR_T{0,1}SZ as 3, not 7.

The T0SZ mask is used to calculate the value for the HTCR, both to pick out
TTBCR.T0SZ and mask off the equivalent field in the HTCR during
read-modify-write. The incorrect mask size causes the (UNKNOWN) reset value
of HTCR.T0SZ to leak in to the calculated HTCR value. Linux will hang when
initializing KVM if HTCR's reset value has bit 2 set (sometimes the case on
A7/TC2)

Fixing T0SZ allows A7 cores to boot and T1SZ is also fixed for completeness.

Signed-off-by: Jonathan Austin <[email protected]>
Acked-by: Marc Zyngier <[email protected]>
Signed-off-by: Christoffer Dall <[email protected]>
  • Loading branch information
jaustin authored and chazy committed Oct 13, 2013
1 parent 1158fca commit 5e49704
Showing 1 changed file with 2 additions and 2 deletions.
4 changes: 2 additions & 2 deletions arch/arm/include/asm/kvm_arm.h
Original file line number Diff line number Diff line change
Expand Up @@ -95,12 +95,12 @@
#define TTBCR_IRGN1 (3 << 24)
#define TTBCR_EPD1 (1 << 23)
#define TTBCR_A1 (1 << 22)
#define TTBCR_T1SZ (3 << 16)
#define TTBCR_T1SZ (7 << 16)
#define TTBCR_SH0 (3 << 12)
#define TTBCR_ORGN0 (3 << 10)
#define TTBCR_IRGN0 (3 << 8)
#define TTBCR_EPD0 (1 << 7)
#define TTBCR_T0SZ 3
#define TTBCR_T0SZ (7 << 0)
#define HTCR_MASK (TTBCR_T0SZ | TTBCR_IRGN0 | TTBCR_ORGN0 | TTBCR_SH0)

/* Hyp System Trap Register */
Expand Down

0 comments on commit 5e49704

Please sign in to comment.