On Mon, May 15, 2017 at 06:43:49PM +0100, James Morse wrote: > KVM uses tpidr_el2 as its private vcpu register, which makes sense for > non-vhe world switch as only KVM can access this register. This means > vhe Linux has to use tpidr_el1, which KVM has to save/restore as part > of the host context. > > __guest_enter() stores the host_ctxt on the stack, do the same with > the vcpu. > > Signed-off-by: James Morse <[email protected]> > --- > arch/arm64/kvm/hyp/entry.S | 12 ++++++++---- > arch/arm64/kvm/hyp/hyp-entry.S | 6 +++--- > 2 files changed, 11 insertions(+), 7 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S > index 12ee62d6d410..113735df7d01 100644 > --- a/arch/arm64/kvm/hyp/entry.S > +++ b/arch/arm64/kvm/hyp/entry.S > @@ -62,8 +62,8 @@ ENTRY(__guest_enter) > // Store the host regs > save_callee_saved_regs x1 > > - // Store the host_ctxt for use at exit time > - str x1, [sp, #-16]! > + // Store host_ctxt and vcpu for use at exit time > + stp x1, x0, [sp, #-16]! > > add x18, x0, #VCPU_CONTEXT > > @@ -159,9 +159,15 @@ abort_guest_exit_end: > ENDPROC(__guest_exit) > > ENTRY(__fpsimd_guest_restore) > + // x0: esr > + // x1: vcpu > + // x2-x29,lr: vcpu regs > + // vcpu x0-x1 on the stack > stp x2, x3, [sp, #-16]! > stp x4, lr, [sp, #-16]! > > + mov x3, x1 > +
nit: can you avoid this by using x1 for the vcpu pointer in this routine instead? > alternative_if_not ARM64_HAS_VIRT_HOST_EXTN > mrs x2, cptr_el2 > bic x2, x2, #CPTR_EL2_TFP > @@ -173,8 +179,6 @@ alternative_else > alternative_endif > isb > > - mrs x3, tpidr_el2 > - > ldr x0, [x3, #VCPU_HOST_CONTEXT] > kern_hyp_va x0 > add x0, x0, #CPU_GP_REG_OFFSET(CPU_FP_REGS) > diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S > index 5170ce1021da..fce7cc507e0a 100644 > --- a/arch/arm64/kvm/hyp/hyp-entry.S > +++ b/arch/arm64/kvm/hyp/hyp-entry.S > @@ -104,6 +104,7 @@ el1_trap: > /* > * x0: ESR_EC > */ > + ldr x1, [sp, #16 + 8] // vcpu stored by __guest_enter > > /* > * We trap the first access to the FP/SIMD to save the host context > @@ -116,19 +117,18 @@ alternative_if_not ARM64_HAS_NO_FPSIMD > b.eq __fpsimd_guest_restore > alternative_else_nop_endif > > - mrs x1, tpidr_el2 > mov x0, #ARM_EXCEPTION_TRAP > b __guest_exit > > el1_irq: > stp x0, x1, [sp, #-16]! > - mrs x1, tpidr_el2 > + ldr x1, [sp, #16 + 8] > mov x0, #ARM_EXCEPTION_IRQ > b __guest_exit > > el1_error: > stp x0, x1, [sp, #-16]! > - mrs x1, tpidr_el2 > + ldr x1, [sp, #16 + 8] > mov x0, #ARM_EXCEPTION_EL1_SERROR > b __guest_exit > > -- > 2.10.1 > Otherwise: Reviewed-by: Christoffer Dall <[email protected]> _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
