Re: [kvm-unit-tests PATCH v1 2/7] arm64: timer: use hypervisor timers when at EL2

[Joey Gouly <joey.gouly@arm.com>]

On Thu, Feb 27, 2025 at 04:55:26PM +0000, Alexandru Elisei wrote:
> Hi Joey,
> 
> On Thu, Feb 20, 2025 at 02:13:49PM +0000, Joey Gouly wrote:
> > At EL2, with VHE:
> >   - CNTP_CVAL_EL0 is forwarded to CNTHP_CVAL_EL0
> >   - CNTV_CVAL_EL0 is forwarded to CNTHP_CVAL_EL0
> 
> CNTH*V*_CVAL_EL0, right?

Fixed.

> 
> It also happens for the other two registers for the physical and virtual
> timers (CNT{P,V}_{TVAL,CTL}_EL0). Just nitpicking here.

I'll write it like that, thanks!

> 
> > 
> > Save the hypervisor physical and virtual timer IRQ numbers from the DT/ACPI.
> > 
> > Signed-off-by: Joey Gouly <joey.gouly@arm.com>
> > ---
> >  arm/timer.c         | 10 ++++++++--
> >  lib/acpi.h          |  2 ++
> >  lib/arm/asm/timer.h | 11 +++++++++++
> >  lib/arm/timer.c     | 19 +++++++++++++++++--
> >  4 files changed, 38 insertions(+), 4 deletions(-)
> > 
> > diff --git a/arm/timer.c b/arm/timer.c
> > index 2cb80518..c6287ca7 100644
> > --- a/arm/timer.c
> > +++ b/arm/timer.c
> > @@ -347,8 +347,14 @@ static void test_ptimer(void)
> >  static void test_init(void)
> >  {
> >  	assert(TIMER_PTIMER_IRQ != -1 && TIMER_VTIMER_IRQ != -1);
It's still there ^^
> > -	ptimer_info.irq = TIMER_PTIMER_IRQ;
> > -	vtimer_info.irq = TIMER_VTIMER_IRQ;
> > +	if (current_level() == CurrentEL_EL1) {
> > +		ptimer_info.irq = TIMER_PTIMER_IRQ;
> > +		vtimer_info.irq = TIMER_VTIMER_IRQ;
> 
> You dropped the assert for TIMER_{P,V}TIMER_IRQ.

The assertion is still there!

> 
> Otherwise, looks good to me:
> 
> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>

Thanks!

> 
> Thanks,
> Alex
> 
> > +	} else {
> > +		assert(TIMER_HPTIMER_IRQ != -1 && TIMER_HVTIMER_IRQ != -1);
> > +		ptimer_info.irq = TIMER_HPTIMER_IRQ;
> > +		vtimer_info.irq = TIMER_HVTIMER_IRQ;
> > +	}
> >  
> >  	install_exception_handler(EL1H_SYNC, ESR_EL1_EC_UNKNOWN, ptimer_unsupported_handler);
> >  	ptimer_info.read_ctl();
> > diff --git a/lib/acpi.h b/lib/acpi.h
> > index c330c877..66e3062d 100644
> > --- a/lib/acpi.h
> > +++ b/lib/acpi.h
> > @@ -290,6 +290,8 @@ struct acpi_table_gtdt {
> >  	u64 counter_read_block_address;
> >  	u32 platform_timer_count;
> >  	u32 platform_timer_offset;
> > +	u32 virtual_el2_timer_interrupt;
> > +	u32 virtual_el2_timer_flags;
> >  };
> >  
> >  /* Reset to default packing */
> > diff --git a/lib/arm/asm/timer.h b/lib/arm/asm/timer.h
> > index aaf839fc..7dda0f4f 100644
> > --- a/lib/arm/asm/timer.h
> > +++ b/lib/arm/asm/timer.h
> > @@ -21,12 +21,23 @@ struct timer_state {
> >  		u32 irq;
> >  		u32 irq_flags;
> >  	} vtimer;
> > +	struct {
> > +		u32 irq;
> > +		u32 irq_flags;
> > +	} hptimer;
> > +	struct {
> > +		u32 irq;
> > +		u32 irq_flags;
> > +	} hvtimer;
> >  };
> >  extern struct timer_state __timer_state;
> >  
> >  #define TIMER_PTIMER_IRQ (__timer_state.ptimer.irq)
> >  #define TIMER_VTIMER_IRQ (__timer_state.vtimer.irq)
> >  
> > +#define TIMER_HPTIMER_IRQ (__timer_state.hptimer.irq)
> > +#define TIMER_HVTIMER_IRQ (__timer_state.hvtimer.irq)
> > +
> >  void timer_save_state(void);
> >  
> >  #endif /* !__ASSEMBLY__ */
> > diff --git a/lib/arm/timer.c b/lib/arm/timer.c
> > index ae702e41..57f504e2 100644
> > --- a/lib/arm/timer.c
> > +++ b/lib/arm/timer.c
> > @@ -38,10 +38,11 @@ static void timer_save_state_fdt(void)
> >  	 *      secure timer irq
> >  	 *      non-secure timer irq            (ptimer)
> >  	 *      virtual timer irq               (vtimer)
> > -	 *      hypervisor timer irq
> > +	 *      hypervisor timer irq            (hptimer)
> > +	 *      hypervisor virtual timer irq    (hvtimer)
> >  	 */
> >  	prop = fdt_get_property(fdt, node, "interrupts", &len);
> > -	assert(prop && len == (4 * 3 * sizeof(u32)));
> > +	assert(prop && len >= (4 * 3 * sizeof(u32)));
> >  
> >  	data = (u32 *) prop->data;
> >  	assert(fdt32_to_cpu(data[3]) == 1 /* PPI */ );
> > @@ -50,6 +51,14 @@ static void timer_save_state_fdt(void)
> >  	assert(fdt32_to_cpu(data[6]) == 1 /* PPI */ );
> >  	__timer_state.vtimer.irq = PPI(fdt32_to_cpu(data[7]));
> >  	__timer_state.vtimer.irq_flags = fdt32_to_cpu(data[8]);
> > +	if (len == (5 * 3 * sizeof(u32))) {
> > +		assert(fdt32_to_cpu(data[9]) == 1 /* PPI */ );
> > +		__timer_state.hptimer.irq = PPI(fdt32_to_cpu(data[10]));
> > +		__timer_state.hptimer.irq_flags = fdt32_to_cpu(data[11]);
> > +		assert(fdt32_to_cpu(data[12]) == 1 /* PPI */ );
> > +		__timer_state.hvtimer.irq = PPI(fdt32_to_cpu(data[13]));
> > +		__timer_state.hvtimer.irq_flags = fdt32_to_cpu(data[14]);
> > +	}
> >  }
> >  
> >  #ifdef CONFIG_EFI
> > @@ -72,6 +81,12 @@ static void timer_save_state_acpi(void)
> >  
> >  	__timer_state.vtimer.irq = gtdt->virtual_timer_interrupt;
> >  	__timer_state.vtimer.irq_flags = gtdt->virtual_timer_flags;
> > +
> > +	__timer_state.hptimer.irq = gtdt->non_secure_el2_interrupt;
> > +	__timer_state.hptimer.irq_flags = gtdt->non_secure_el2_flags;
> > +
> > +	__timer_state.hvtimer.irq = gtdt->virtual_el2_timer_interrupt;
> > +	__timer_state.hvtimer.irq_flags = gtdt->virtual_el2_timer_flags;
> >  }
> >  
> >  #else
> > -- 
> > 2.25.1
> >