On Wed, 08 Jun 2022 16:16:16 +0100,
Fuad Tabba <tabba@xxxxxxxxxx> wrote:
>
> Hi Marc,
>
> On Sat, May 28, 2022 at 12:38 PM Marc Zyngier <maz@xxxxxxxxxx> wrote:
> >
> > The three debug flags (which deal with the debug registers, SPE and
> > TRBE) all are input flags to the hypervisor code.
> >
> > Move them into the input set and convert them to the new accessors.
> >
> > Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
> > ---
> > arch/arm64/include/asm/kvm_host.h | 9 ++++++---
> > arch/arm64/kvm/debug.c | 22 +++++++++++-----------
> > arch/arm64/kvm/hyp/include/hyp/debug-sr.h | 6 +++---
> > arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 4 ++--
> > arch/arm64/kvm/hyp/nvhe/debug-sr.c | 8 ++++----
> > arch/arm64/kvm/sys_regs.c | 8 ++++----
> > 6 files changed, 30 insertions(+), 27 deletions(-)
> >
> > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> > index 078567f5709c..a426cd3aaa74 100644
> > --- a/arch/arm64/include/asm/kvm_host.h
> > +++ b/arch/arm64/include/asm/kvm_host.h
> > @@ -500,6 +500,12 @@ struct kvm_vcpu_arch {
> > #define EXCEPT_AA64_EL2_IRQ __vcpu_except_flags(5)
> > #define EXCEPT_AA64_EL2_FIQ __vcpu_except_flags(6)
> > #define EXCEPT_AA64_EL2_SERR __vcpu_except_flags(7)
> > +/* Guest debug is live */
> > +#define DEBUG_DIRTY __vcpu_single_flag(iflags, BIT(4))
> > +/* Save SPE context if active */
> > +#define DEBUG_STATE_SAVE_SPE __vcpu_single_flag(iflags, BIT(5))
> > +/* Save TRBE context if active */
> > +#define DEBUG_STATE_SAVE_TRBE __vcpu_single_flag(iflags, BIT(6))
> >
> > /* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */
> > #define vcpu_sve_pffr(vcpu) (kern_hyp_va((vcpu)->arch.sve_state) + \
> > @@ -522,10 +528,7 @@ struct kvm_vcpu_arch {
> > })
> >
> > /* vcpu_arch flags field values: */
> > -#define KVM_ARM64_DEBUG_DIRTY (1 << 0)
> > #define KVM_ARM64_HOST_SVE_ENABLED (1 << 4) /* SVE enabled for EL0 */
> > -#define KVM_ARM64_DEBUG_STATE_SAVE_SPE (1 << 12) /* Save SPE context if active */
> > -#define KVM_ARM64_DEBUG_STATE_SAVE_TRBE (1 << 13) /* Save TRBE context if active */
> > #define KVM_ARM64_ON_UNSUPPORTED_CPU (1 << 15) /* Physical CPU not in supported_cpus */
> > #define KVM_ARM64_HOST_SME_ENABLED (1 << 16) /* SME enabled for EL0 */
> > #define KVM_ARM64_WFIT (1 << 17) /* WFIT instruction trapped */
> > diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
> > index 4fd5c216c4bb..c5c4c1837bf3 100644
> > --- a/arch/arm64/kvm/debug.c
> > +++ b/arch/arm64/kvm/debug.c
> > @@ -104,11 +104,11 @@ static void kvm_arm_setup_mdcr_el2(struct kvm_vcpu *vcpu)
> > * Trap debug register access when one of the following is true:
> > * - Userspace is using the hardware to debug the guest
> > * (KVM_GUESTDBG_USE_HW is set).
> > - * - The guest is not using debug (KVM_ARM64_DEBUG_DIRTY is clear).
> > + * - The guest is not using debug (DEBUG_DIRTY clear).
> > * - The guest has enabled the OS Lock (debug exceptions are blocked).
> > */
> > if ((vcpu->guest_debug & KVM_GUESTDBG_USE_HW) ||
> > - !(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY) ||
> > + !vcpu_get_flag(vcpu, DEBUG_DIRTY) ||
> > kvm_vcpu_os_lock_enabled(vcpu))
> > vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA;
> >
> > @@ -147,8 +147,8 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu)
> > * debug related registers.
> > *
> > * Additionally, KVM only traps guest accesses to the debug registers if
> > - * the guest is not actively using them (see the KVM_ARM64_DEBUG_DIRTY
> > - * flag on vcpu->arch.flags). Since the guest must not interfere
> > + * the guest is not actively using them (see the DEBUG_DIRTY
> > + * flag on vcpu->arch.iflags). Since the guest must not interfere
> > * with the hardware state when debugging the guest, we must ensure that
> > * trapping is enabled whenever we are debugging the guest using the
> > * debug registers.
> > @@ -205,7 +205,7 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
> > *
> > * We simply switch the debug_ptr to point to our new
> > * external_debug_state which has been populated by the
> > - * debug ioctl. The existing KVM_ARM64_DEBUG_DIRTY
> > + * debug ioctl. The existing KVM_ARM64_IFLAG_DEBUG_DIRTY
>
> This should be DEBUG_DIRTY.
Ah, nice catch. That's a left-over from a previous implementation that
didn't have the notion of flag-set built-in.
There is also another one of these in kvm_host.h, which I will fix as
well.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
