On Mon, Jan 25, 2016 at 03:53:39PM +0000, Marc Zyngier wrote: > On a VHE-capable system, there is no point in setting VTCR_EL2 > at KVM init time. We can perfectly set it up when the kernel > boots, removing the need for a more complicated configuration.
what's the complicated configuration which is avoided? > > In order to allow this, turn VTCR_EL2 setup into a macro that > we'll be able to reuse at boot time. > > Signed-off-by: Marc Zyngier <marc.zyng...@arm.com> > --- > arch/arm64/include/asm/kvm_mmu.h | 23 +++++++++++++++++++++++ > arch/arm64/kvm/hyp-init.S | 18 +----------------- > 2 files changed, 24 insertions(+), 17 deletions(-) > > diff --git a/arch/arm64/include/asm/kvm_mmu.h > b/arch/arm64/include/asm/kvm_mmu.h > index 7364339..d3e6d7b 100644 > --- a/arch/arm64/include/asm/kvm_mmu.h > +++ b/arch/arm64/include/asm/kvm_mmu.h > @@ -56,6 +56,29 @@ > > #ifdef __ASSEMBLY__ > > +#include <asm/kvm_arm.h> > + > +.macro setup_vtcr tmp1, tmp2 > + mov \tmp1, #(VTCR_EL2_FLAGS & 0xffff) > + movk \tmp1, #(VTCR_EL2_FLAGS >> 16), lsl #16 > + /* > + * Read the PARange bits from ID_AA64MMFR0_EL1 and set the PS bits in > + * VTCR_EL2. > + */ > + mrs \tmp2, id_aa64mmfr0_el1 > + bfi \tmp1, \tmp2, #16, #3 > + /* > + * Read the VMIDBits bits from ID_AA64MMFR1_EL1 and set the VS bit in > + * VTCR_EL2. > + */ > + mrs \tmp2, ID_AA64MMFR1_EL1 > + ubfx \tmp2, \tmp2, #5, #1 > + lsl \tmp2, \tmp2, #VTCR_EL2_VS > + orr \tmp1, \tmp1, \tmp2 > + > + msr vtcr_el2, \tmp1 > + isb > +.endm this feels like an awful lot of code in a header file. Is it crazy to imagine wanting to have different T0SZ for different VMs in the future? In that case, the T0SZ stuff should stay in KVM... Thanks, -Christoffer > /* > * Convert a kernel VA into a HYP VA. > * reg: VA to be converted. > diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S > index 3e568dc..4143e2c 100644 > --- a/arch/arm64/kvm/hyp-init.S > +++ b/arch/arm64/kvm/hyp-init.S > @@ -87,23 +87,7 @@ __do_hyp_init: > #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. > - */ > - mrs x5, ID_AA64MMFR0_EL1 > - bfi x4, x5, #16, #3 > - /* > - * Read the VMIDBits bits from ID_AA64MMFR1_EL1 and set the VS bit in > - * VTCR_EL2. > - */ > - mrs x5, ID_AA64MMFR1_EL1 > - ubfx x5, x5, #5, #1 > - lsl x5, x5, #VTCR_EL2_VS > - orr x4, x4, x5 > - > - msr vtcr_el2, x4 > + setup_vtcr x4, x5 > > mrs x4, mair_el1 > msr mair_el2, x4 > -- > 2.1.4 >
