| Message ID | 1380210568-23175-2-git-send-email-jonathan.austin@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Sep 26, 2013 at 04:49:26PM +0100, Jonathan Austin wrote: > 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 <jonathan.austin@arm.com> > Acked-by: Marc Zyngier <marc.zyngier@arm.com> > --- > arch/arm/include/asm/kvm_arm.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h > index 64e9696..d556f03 100644 > --- a/arch/arm/include/asm/kvm_arm.h > +++ b/arch/arm/include/asm/kvm_arm.h > @@ -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 */ > -- > 1.7.9.5 > Good catch! ack. -Christoffer
diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h index 64e9696..d556f03 100644 --- a/arch/arm/include/asm/kvm_arm.h +++ b/arch/arm/include/asm/kvm_arm.h @@ -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 */
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 <jonathan.austin@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> --- arch/arm/include/asm/kvm_arm.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)