On Wed, Mar 10, 2021 at 05:49:17PM +0000, Marc Zyngier wrote: > On Wed, 10 Mar 2021 16:15:47 +0000, > Will Deacon <will@xxxxxxxxxx> wrote: > > On Wed, Mar 10, 2021 at 04:05:17PM +0000, Marc Zyngier wrote: > > > On Wed, 10 Mar 2021 15:46:26 +0000, > > > Will Deacon <will@xxxxxxxxxx> wrote: > > > > On Wed, Mar 10, 2021 at 03:26:55PM +0000, Marc Zyngier wrote: > > > > > diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S > > > > > index 4eb584ae13d9..7423f4d961a4 100644 > > > > > --- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S > > > > > +++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S > > > > > @@ -122,7 +122,7 @@ alternative_else_nop_endif > > > > > * as well as the EE bit on BE. Drop the A flag since the compiler > > > > > * is allowed to generate unaligned accesses. > > > > > */ > > > > > - mov_q x0, (SCTLR_EL2_RES1 | (SCTLR_ELx_FLAGS & ~SCTLR_ELx_A)) > > > > > + mov_q x0, (SCTLR_EL2_RES1 | (SCTLR_EL2_FLAGS & ~SCTLR_ELx_A)) > > > > > > > > Can we just drop SCTLR_ELx_A from SCTLR_EL2_FLAGS instead of clearing it > > > > here? > > > > > > Absolutely. That'd actually be an improvement. > > > > In fact, maybe just define INIT_SCTLR_EL2_MMU_ON to mirror what we do for > > EL1 (i.e. including the RES1 bits) and then use that here? > > Like this? > > diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h > index dfd4edbfe360..593b9bf91bbd 100644 > --- a/arch/arm64/include/asm/sysreg.h > +++ b/arch/arm64/include/asm/sysreg.h > @@ -579,9 +579,6 @@ > #define SCTLR_ELx_A (BIT(1)) > #define SCTLR_ELx_M (BIT(0)) > > -#define SCTLR_ELx_FLAGS (SCTLR_ELx_M | SCTLR_ELx_A | SCTLR_ELx_C | \ > - SCTLR_ELx_SA | SCTLR_ELx_I | SCTLR_ELx_IESB) > - > /* SCTLR_EL2 specific flags. */ > #define SCTLR_EL2_RES1 ((BIT(4)) | (BIT(5)) | (BIT(11)) | (BIT(16)) | \ > (BIT(18)) | (BIT(22)) | (BIT(23)) | (BIT(28)) | \ > @@ -593,6 +590,10 @@ > #define ENDIAN_SET_EL2 0 > #endif > > +#define INIT_SCTLR_EL2_MMU_ON \ > + (SCTLR_ELx_M | SCTLR_ELx_C | SCTLR_ELx_SA | SCTLR_ELx_I | \ > + SCTLR_ELx_IESB | ENDIAN_SET_EL2 | SCTLR_EL2_RES1) > + > #define INIT_SCTLR_EL2_MMU_OFF \ > (SCTLR_EL2_RES1 | ENDIAN_SET_EL2) > > diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S > index 4eb584ae13d9..2e16b2098bbd 100644 > --- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S > +++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S > @@ -117,13 +117,7 @@ alternative_else_nop_endif > tlbi alle2 > dsb sy > > - /* > - * Preserve all the RES1 bits while setting the default flags, > - * as well as the EE bit on BE. Drop the A flag since the compiler > - * is allowed to generate unaligned accesses. > - */ > - mov_q x0, (SCTLR_EL2_RES1 | (SCTLR_ELx_FLAGS & ~SCTLR_ELx_A)) > -CPU_BE( orr x0, x0, #SCTLR_ELx_EE) > + mov_q x0, INIT_SCTLR_EL2_MMU_ON > alternative_if ARM64_HAS_ADDRESS_AUTH > mov_q x1, (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | \ > SCTLR_ELx_ENDA | SCTLR_ELx_ENDB) Beautiful! With that, you can have my ack on the whole series: Acked-by: Will Deacon <will@xxxxxxxxxx> Will
