On Mon, Jun 22, 2015 at 06:41:34PM +0800, Zhichao Huang wrote: > Enable trapping of the debug registers, allowing guests to use > the debug infrastructure. > > Signed-off-by: Zhichao Huang <[email protected]> > --- > arch/arm/kvm/interrupts_head.S | 15 +++++++++++++-- > 1 file changed, 13 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S > index ed406be..107bda4 100644 > --- a/arch/arm/kvm/interrupts_head.S > +++ b/arch/arm/kvm/interrupts_head.S > @@ -886,10 +886,21 @@ ARM_BE8(rev r6, r6 ) > .endm > > /* Configures the HDCR (Hyp Debug Configuration Register) on entry/return > - * (hardware reset value is 0) */ > + * (hardware reset value is 0) > + * > + * Clobbers r2-r4 > + */ > .macro set_hdcr operation > mrc p15, 4, r2, c1, c1, 1 > - ldr r3, =(HDCR_TPM|HDCR_TPMCR) > + ldr r3, =(HDCR_TPM|HDCR_TPMCR|HDCR_TDRA|HDCR_TDOSA) > + > + // Check for KVM_ARM_DEBUG_DIRTY, and set debug to trap > + // if not dirty. > + ldr r4, [vcpu, #VCPU_DEBUG_FLAGS] > + cmp r4, #KVM_ARM_DEBUG_DIRTY > + beq 1f > + orr r3, r3, #HDCR_TDA > +1:
It may make me slightly more calm if you always unconditionally clear HDCR_TDA on vmexit, but ok. > .if \operation == vmentry > orr r2, r2, r3 @ Trap some perfmon accesses > .else > -- > 1.7.12.4 > Reviewed-by: Christoffer Dall <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
