[PATCH v4 15/15] KVM: arm: enable trapping of all debug registers
From: Christoffer Dall <hidden>
Date: 2015-09-02 16:08:14
Also in:
kvm, kvmarm
On Mon, Aug 10, 2015 at 09:26:07PM +0800, Zhichao Huang wrote:
quoted hunk ↗ jump to hunk
Enable trapping of the debug registers unconditionally, allowing guests to use the debug infrastructure. Signed-off-by: Zhichao Huang <redacted> Reviewed-by: Christoffer Dall <redacted> --- arch/arm/kvm/interrupts_head.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S index 7ad0adf..494991d 100644 --- a/arch/arm/kvm/interrupts_head.S +++ b/arch/arm/kvm/interrupts_head.S@@ -792,7 +792,7 @@ ARM_BE8(rev r6, r6 ) * (hardware reset value is 0) */ .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|HDCR_TDA)
eh, but I thought we didn't have to trap accesses to the debug registers if we switch them, because the guest is likely to be using them? Maybe I am getting confused, can you repeat for me exactly when we context-switch the registers and when we trap accesses to them? Thanks, -Christoffer
.if \operation == vmentry orr r2, r2, r3 @ Trap some perfmon accesses .else -- 1.7.12.4