On Thu, Feb 08, 2018 at 05:22:29PM +0000, Suzuki K Poulose wrote: > On 08/02/18 11:00, Christoffer Dall wrote: > >On Tue, Jan 09, 2018 at 07:04:09PM +0000, Suzuki K Poulose wrote: > >>Now that we can manage the stage2 page table per VM, switch the > >>configuration details to per VM instance. We keep track of the > >>IPA bits, number of page table levels and the VTCR bits (which > >>depends on the IPA and the number of levels). > >> > >>Cc: Marc Zyngier <marc.zyngier@xxxxxxx> > >>Cc: Christoffer Dall <cdall@xxxxxxxxxx> > >>Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx> > >>--- > >> arch/arm/include/asm/kvm_mmu.h | 1 + > >> arch/arm64/include/asm/kvm_host.h | 12 ++++++++++++ > >> arch/arm64/include/asm/kvm_mmu.h | 22 ++++++++++++++++++++-- > >> arch/arm64/include/asm/stage2_pgtable.h | 1 - > >> arch/arm64/kvm/hyp/switch.c | 3 +-- > >> virt/kvm/arm/arm.c | 2 +- > >> 6 files changed, 35 insertions(+), 6 deletions(-) > >> > >>diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h > >>index 440c80589453..dd592fe45660 100644 > >>--- a/arch/arm/include/asm/kvm_mmu.h > >>+++ b/arch/arm/include/asm/kvm_mmu.h > >>@@ -48,6 +48,7 @@ > >> #define kvm_vttbr_baddr_mask(kvm) VTTBR_BADDR_MASK > >> #define stage2_pgd_size(kvm) (PTRS_PER_S2_PGD * sizeof(pgd_t)) > >>+#define kvm_init_stage2_config(kvm) do { } while (0) > >> int create_hyp_mappings(void *from, void *to, pgprot_t prot); > >> int create_hyp_io_mappings(void *from, void *to, phys_addr_t); > >> void free_hyp_pgds(void); > >>diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > >>index 9a9ddeb33c84..1e66e5ab3dde 100644 > >>--- a/arch/arm64/include/asm/kvm_host.h > >>+++ b/arch/arm64/include/asm/kvm_host.h > >>@@ -64,6 +64,18 @@ struct kvm_arch { > >> /* VTTBR value associated with above pgd and vmid */ > >> u64 vttbr; > >>+ /* Private bits of VTCR_EL2 for this VM */ > >>+ u64 vtcr_private; > > > >As to my comments in the previous patch, why isn't this simply u64 vtcr; > > nit: I haven't received your response to the previous patch. It got stuck in my drafts folder somehow, hopefully you received it now. > > We could. I thought this gives a bit more clarity on what changes per-VM. > Since there's a performance issue involved, I think it's cleaner to just calculate the vtcr once per VM and store it. Thanks, -Christoffer