The code was writing back the register, even for writes and didn''t
implement
CNTPCT at all.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
---
xen/arch/arm/vtimer.c | 51 ++++++++++++++++++++++++++++++++++---------------
1 file changed, 36 insertions(+), 15 deletions(-)
diff --git a/xen/arch/arm/vtimer.c b/xen/arch/arm/vtimer.c
index f323453..dcda2b2 100644
--- a/xen/arch/arm/vtimer.c
+++ b/xen/arch/arm/vtimer.c
@@ -165,6 +165,27 @@ static void vtimer_cntp_tval(struct cpu_user_regs *regs,
uint32_t *r, int read)
}
}
+static int vtimer_cntpct(struct cpu_user_regs *regs, uint64_t *r, int read)
+{
+ struct vcpu *v = current;
+ uint64_t ticks;
+ s_time_t now;
+
+ if ( read )
+ {
+ now = NOW() - v->domain->arch.phys_timer_base.offset;
+ ticks = ns_to_ticks(now);
+ *r = ticks;
+ return 1;
+ }
+ else
+ {
+ gdprintk(XENLOG_DEBUG, "READ from R/O CNTPCT\n");
+ return 0;
+ }
+}
+
+
static int vtimer_emulate_cp32(struct cpu_user_regs *regs, union hsr hsr)
{
struct hsr_cp32 cp32 = hsr.cp32;
@@ -187,29 +208,23 @@ static int vtimer_emulate_cp32(struct cpu_user_regs *regs,
union hsr hsr)
static int vtimer_emulate_cp64(struct cpu_user_regs *regs, union hsr hsr)
{
- struct vcpu *v = current;
struct hsr_cp64 cp64 = hsr.cp64;
uint32_t *r1 = (uint32_t *)select_user_reg(regs, cp64.reg1);
uint32_t *r2 = (uint32_t *)select_user_reg(regs, cp64.reg2);
- uint64_t ticks;
- s_time_t now;
+ uint64_t x;
switch ( hsr.bits & HSR_CP64_REGS_MASK )
{
case HSR_CPREG64(CNTPCT):
+ if (!vtimer_cntpct(regs, &x, cp64.read))
+ return 0;
+
if ( cp64.read )
{
- now = NOW() - v->domain->arch.phys_timer_base.offset;
- ticks = ns_to_ticks(now);
- *r1 = (uint32_t)(ticks & 0xffffffff);
- *r2 = (uint32_t)(ticks >> 32);
- return 1;
- }
- else
- {
- printk("READ from R/O CNTPCT\n");
- return 0;
+ *r1 = (uint32_t)(x & 0xffffffff);
+ *r2 = (uint32_t)(x >> 32);
}
+ return 1;
default:
return 0;
@@ -227,12 +242,18 @@ static int vtimer_emulate_sysreg(struct cpu_user_regs
*regs, union hsr hsr)
{
case CNTP_CTL_EL0:
vtimer_cntp_ctl(regs, &r, sysreg.read);
- *x = r;
+ if ( sysreg.read )
+ *x = r;
return 1;
case CNTP_TVAL_EL0:
vtimer_cntp_tval(regs, &r, sysreg.read);
- *x = r;
+ if ( sysreg.read )
+ *x = r;
return 1;
+
+ case HSR_CPREG64(CNTPCT):
+ return vtimer_cntpct(regs, x, sysreg.read);
+
default:
return 0;
}
--
1.7.10.4
On 12/05/2013 12:58 PM, Ian Campbell wrote:> The code was writing back the register, even for writes and didn''t implement > CNTPCT at all. > > Signed-off-by: Ian Campbell <ian.campbell@citrix.com> > --- > xen/arch/arm/vtimer.c | 51 ++++++++++++++++++++++++++++++++++--------------- > 1 file changed, 36 insertions(+), 15 deletions(-) > > diff --git a/xen/arch/arm/vtimer.c b/xen/arch/arm/vtimer.c > index f323453..dcda2b2 100644 > --- a/xen/arch/arm/vtimer.c > +++ b/xen/arch/arm/vtimer.c > @@ -165,6 +165,27 @@ static void vtimer_cntp_tval(struct cpu_user_regs *regs, uint32_t *r, int read) > } > } > > +static int vtimer_cntpct(struct cpu_user_regs *regs, uint64_t *r, int read) > +{ > + struct vcpu *v = current; > + uint64_t ticks; > + s_time_t now; > + > + if ( read ) > + { > + now = NOW() - v->domain->arch.phys_timer_base.offset; > + ticks = ns_to_ticks(now); > + *r = ticks; > + return 1; > + } > + else > + { > + gdprintk(XENLOG_DEBUG, "READ from R/O CNTPCT\n");s/READ/WRITE/ ? Except this minor typo: Acked-by: Julien Grall <julien.grall@linaro.org> -- Julien Grall
On Fri, 2013-12-06 at 16:30 +0000, Julien Grall wrote:> > On 12/05/2013 12:58 PM, Ian Campbell wrote: > > The code was writing back the register, even for writes and didn''t implement > > CNTPCT at all. > > > > Signed-off-by: Ian Campbell <ian.campbell@citrix.com> > > --- > > xen/arch/arm/vtimer.c | 51 ++++++++++++++++++++++++++++++++++--------------- > > 1 file changed, 36 insertions(+), 15 deletions(-) > > > > diff --git a/xen/arch/arm/vtimer.c b/xen/arch/arm/vtimer.c > > index f323453..dcda2b2 100644 > > --- a/xen/arch/arm/vtimer.c > > +++ b/xen/arch/arm/vtimer.c > > @@ -165,6 +165,27 @@ static void vtimer_cntp_tval(struct cpu_user_regs *regs, uint32_t *r, int read) > > } > > } > > > > +static int vtimer_cntpct(struct cpu_user_regs *regs, uint64_t *r, int read) > > +{ > > + struct vcpu *v = current; > > + uint64_t ticks; > > + s_time_t now; > > + > > + if ( read ) > > + { > > + now = NOW() - v->domain->arch.phys_timer_base.offset; > > + ticks = ns_to_ticks(now); > > + *r = ticks; > > + return 1; > > + } > > + else > > + { > > + gdprintk(XENLOG_DEBUG, "READ from R/O CNTPCT\n"); > > s/READ/WRITE/ ?Yeah, copied blindly from the existing wrong code!> Except this minor typo: > > Acked-by: Julien Grall <julien.grall@linaro.org>Thanks.
On Thu, 5 Dec 2013, Ian Campbell wrote:> @@ -227,12 +242,18 @@ static int vtimer_emulate_sysreg(struct cpu_user_regs *regs, union hsr hsr) > { > case CNTP_CTL_EL0: > vtimer_cntp_ctl(regs, &r, sysreg.read); > - *x = r; > + if ( sysreg.read ) > + *x = r; > return 1; > case CNTP_TVAL_EL0: > vtimer_cntp_tval(regs, &r, sysreg.read); > - *x = r; > + if ( sysreg.read ) > + *x = r; > return 1;Are you sure that sysreg.read == 1 means write? From xen/arch/arm/traps.c:do_sysreg: printk("%s %d, %d, c%d, c%d, %d %s x%d @ 0x%"PRIregister"\n", sysreg.read ? "mrs" : "msr", sysreg.read == 1 -> mrs that is a read from special register.
On Fri, 2013-12-06 at 17:38 +0000, Stefano Stabellini wrote:> On Thu, 5 Dec 2013, Ian Campbell wrote: > > @@ -227,12 +242,18 @@ static int vtimer_emulate_sysreg(struct cpu_user_regs *regs, union hsr hsr) > > { > > case CNTP_CTL_EL0: > > vtimer_cntp_ctl(regs, &r, sysreg.read); > > - *x = r; > > + if ( sysreg.read ) > > + *x = r; > > return 1; > > case CNTP_TVAL_EL0: > > vtimer_cntp_tval(regs, &r, sysreg.read); > > - *x = r; > > + if ( sysreg.read ) > > + *x = r; > > return 1; > > Are you sure that sysreg.read == 1 means write?On the contrary, it means read. Here x points to the guest reg that is the target of the read, and r is the new value which the emulation has produced. So *x = r is implementing a read from the guest''s PoV. Ian.
On Fri, 6 Dec 2013, Ian Campbell wrote:> On Fri, 2013-12-06 at 17:38 +0000, Stefano Stabellini wrote: > > On Thu, 5 Dec 2013, Ian Campbell wrote: > > > @@ -227,12 +242,18 @@ static int vtimer_emulate_sysreg(struct cpu_user_regs *regs, union hsr hsr) > > > { > > > case CNTP_CTL_EL0: > > > vtimer_cntp_ctl(regs, &r, sysreg.read); > > > - *x = r; > > > + if ( sysreg.read ) > > > + *x = r; > > > return 1; > > > case CNTP_TVAL_EL0: > > > vtimer_cntp_tval(regs, &r, sysreg.read); > > > - *x = r; > > > + if ( sysreg.read ) > > > + *x = r; > > > return 1; > > > > Are you sure that sysreg.read == 1 means write? > > On the contrary, it means read. > > Here x points to the guest reg that is the target of the read, and r is > the new value which the emulation has produced. > > So *x = r is implementing a read from the guest''s PoV.Ops, that''s right. Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>