On Wed, Feb 10, 2016 at 10:46:53AM -0800, tchalamarla@xxxxxxxxxxxxxxxxxx wrote: > From: Tirumalesh Chalamarla <tchalamarla@xxxxxxxxxxxxxxxxxx> > > Setting TCR_EL2.PS to 40 bits is wrong on systems with PS size is > less than 40 bits. and with systems where RAM is at higher address, > this will break KVM. > > This patch sets TCR_EL2.PS at runtime similar to VTCR_EL2.PS > > changes form V2: > - Modified subject line and commit message. > - Removed TCR_EL2_FLAGS. > > changes from V1: > - Moved to dynamic configuration. > > Signed-off-by: Tirumalesh Chalamarla <tchalamarla@xxxxxxxxxxxxxxxxxx> > --- > arch/arm64/include/asm/kvm_arm.h | 2 -- > arch/arm64/kvm/hyp-init.S | 12 +++++++----- > 2 files changed, 7 insertions(+), 7 deletions(-) > > diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h > index 738a95f..3776db0 100644 > --- a/arch/arm64/include/asm/kvm_arm.h > +++ b/arch/arm64/include/asm/kvm_arm.h > @@ -107,8 +107,6 @@ > #define TCR_EL2_MASK (TCR_EL2_TG0 | TCR_EL2_SH0 | \ > TCR_EL2_ORGN0 | TCR_EL2_IRGN0 | TCR_EL2_T0SZ) > > -#define TCR_EL2_FLAGS (TCR_EL2_RES1 | TCR_EL2_PS_40B) > - > /* VTCR_EL2 Registers bits */ > #define VTCR_EL2_RES1 (1 << 31) > #define VTCR_EL2_PS_MASK (7 << 16) > diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S > index 3e568dc..b5ab1b0 100644 > --- a/arch/arm64/kvm/hyp-init.S > +++ b/arch/arm64/kvm/hyp-init.S > @@ -64,7 +64,7 @@ __do_hyp_init: > mrs x4, tcr_el1 > ldr x5, =TCR_EL2_MASK > and x4, x4, x5 > - ldr x5, =TCR_EL2_FLAGS > + ldr x5, =TCR_EL2_RES1 > orr x4, x4, x5 > > #ifndef CONFIG_ARM64_VA_BITS_48 > @@ -85,15 +85,17 @@ __do_hyp_init: > ldr_l x5, idmap_t0sz > bfi x4, x5, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH > #endif > - msr tcr_el2, x4 > - > - ldr x4, =VTCR_EL2_FLAGS > /* > * Read the PARange bits from ID_AA64MMFR0_EL1 and set the PS bits in > - * VTCR_EL2. > + * TCR_EL2 and VTCR_EL2. > */ > mrs x5, ID_AA64MMFR0_EL1 > bfi x4, x5, #16, #3 > + > + msr tcr_el2, x4 > + > + ldr x4, =VTCR_EL2_FLAGS > + bfi x4, x5, #16, #3 > /* > * Read the VMIDBits bits from ID_AA64MMFR1_EL1 and set the VS bit in > * VTCR_EL2. > -- > 2.1.0 > This looks reasonable enough for me. Did we limit Linux to PS=40 bits in the past and have lifted this restriction, or why did we have this limitation for EL2 translations in the past? Thanks, -Christoffer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
