* [PATCH] KVM: LAPIC: ARBPRI is a reserved register for x2APIC
@ 2019-07-05 12:14 Paolo Bonzini
2019-07-05 12:37 ` Liran Alon
2019-07-05 13:37 ` Nadav Amit
0 siblings, 2 replies; 6+ messages in thread
From: Paolo Bonzini @ 2019-07-05 12:14 UTC (permalink / raw)
To: linux-kernel, kvm
kvm-unit-tests were adjusted to match bare metal behavior, but KVM
itself was not doing what bare metal does; fix that.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/lapic.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index d6ca5c4f29f1..2e4470f2685a 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1318,7 +1318,7 @@ int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len,
unsigned char alignment = offset & 0xf;
u32 result;
/* this bitmask has a bit cleared for each reserved register */
- static const u64 rmask = 0x43ff01ffffffe70cULL;
+ u64 rmask = 0x43ff01ffffffe70cULL;
if ((alignment + len) > 4) {
apic_debug("KVM_APIC_READ: alignment error %x %d\n",
@@ -1326,6 +1326,10 @@ int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len,
return 1;
}
+ /* ARBPRI is also reserved on x2APIC */
+ if (apic_x2apic_mode(apic))
+ rmask &= ~(1 << (APIC_ARBPRI >> 4));
+
if (offset > 0x3f0 || !(rmask & (1ULL << (offset >> 4)))) {
apic_debug("KVM_APIC_READ: read reserved register %x\n",
offset);
--
1.8.3.1
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] KVM: LAPIC: ARBPRI is a reserved register for x2APIC
2019-07-05 12:14 [PATCH] KVM: LAPIC: ARBPRI is a reserved register for x2APIC Paolo Bonzini
@ 2019-07-05 12:37 ` Liran Alon
2019-07-05 12:46 ` Paolo Bonzini
2019-07-05 13:37 ` Nadav Amit
1 sibling, 1 reply; 6+ messages in thread
From: Liran Alon @ 2019-07-05 12:37 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: linux-kernel, kvm
> On 5 Jul 2019, at 15:14, Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> kvm-unit-tests were adjusted to match bare metal behavior, but KVM
> itself was not doing what bare metal does; fix that.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> arch/x86/kvm/lapic.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index d6ca5c4f29f1..2e4470f2685a 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -1318,7 +1318,7 @@ int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len,
> unsigned char alignment = offset & 0xf;
> u32 result;
> /* this bitmask has a bit cleared for each reserved register */
> - static const u64 rmask = 0x43ff01ffffffe70cULL;
> + u64 rmask = 0x43ff01ffffffe70cULL;
Why not rename this to “used_bits_mask” and calculate it properly by macros?
It seems a lot nicer than having a pre-calculated magic.
-Liran
>
> if ((alignment + len) > 4) {
> apic_debug("KVM_APIC_READ: alignment error %x %d\n",
> @@ -1326,6 +1326,10 @@ int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len,
> return 1;
> }
>
> + /* ARBPRI is also reserved on x2APIC */
> + if (apic_x2apic_mode(apic))
> + rmask &= ~(1 << (APIC_ARBPRI >> 4));
> +
> if (offset > 0x3f0 || !(rmask & (1ULL << (offset >> 4)))) {
> apic_debug("KVM_APIC_READ: read reserved register %x\n",
> offset);
> --
> 1.8.3.1
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] KVM: LAPIC: ARBPRI is a reserved register for x2APIC
2019-07-05 12:37 ` Liran Alon
@ 2019-07-05 12:46 ` Paolo Bonzini
0 siblings, 0 replies; 6+ messages in thread
From: Paolo Bonzini @ 2019-07-05 12:46 UTC (permalink / raw)
To: Liran Alon; +Cc: linux-kernel, kvm
On 05/07/19 14:37, Liran Alon wrote:
>> + u64 rmask = 0x43ff01ffffffe70cULL;
> Why not rename this to “used_bits_mask” and calculate it properly by macros?
> It seems a lot nicer than having a pre-calculated magic.
Yes, I wanted to do the same but I didn't have time right now. I am
planning to cleanup after the merge window, but if a patch comes soon I
can apply it instead of course. :)
Something like
#define APIC_VALID_REG_MASK(reg) (1ull << ((reg) >> 4))
#define APIC_VALID_REGS_MASK(first, count) \
(APIC_VALID_REG_MASK(first) * (1ull << ((count) - 1)))
followed by
if (offset > 0x3f0 ||
!(valid_regs_mask & APIC_VALID_REG_MASK(offset))
Paolo
> -Liran
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: LAPIC: ARBPRI is a reserved register for x2APIC
2019-07-05 12:14 [PATCH] KVM: LAPIC: ARBPRI is a reserved register for x2APIC Paolo Bonzini
2019-07-05 12:37 ` Liran Alon
@ 2019-07-05 13:37 ` Nadav Amit
2019-07-05 13:43 ` Paolo Bonzini
1 sibling, 1 reply; 6+ messages in thread
From: Nadav Amit @ 2019-07-05 13:37 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: LKML, kvm
> On Jul 5, 2019, at 5:14 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> kvm-unit-tests were adjusted to match bare metal behavior, but KVM
> itself was not doing what bare metal does; fix that.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reported-by ?
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: LAPIC: ARBPRI is a reserved register for x2APIC
2019-07-05 13:37 ` Nadav Amit
@ 2019-07-05 13:43 ` Paolo Bonzini
2019-07-05 13:47 ` Nadav Amit
0 siblings, 1 reply; 6+ messages in thread
From: Paolo Bonzini @ 2019-07-05 13:43 UTC (permalink / raw)
To: Nadav Amit; +Cc: LKML, kvm
On 05/07/19 15:37, Nadav Amit wrote:
>> On Jul 5, 2019, at 5:14 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>>
>> kvm-unit-tests were adjusted to match bare metal behavior, but KVM
>> itself was not doing what bare metal does; fix that.
>>
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>
> Reported-by ?
I found it myself while running the tests, was there a report too?
Paolo
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: LAPIC: ARBPRI is a reserved register for x2APIC
2019-07-05 13:43 ` Paolo Bonzini
@ 2019-07-05 13:47 ` Nadav Amit
0 siblings, 0 replies; 6+ messages in thread
From: Nadav Amit @ 2019-07-05 13:47 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: LKML, kvm
> On Jul 5, 2019, at 6:43 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> On 05/07/19 15:37, Nadav Amit wrote:
>>> On Jul 5, 2019, at 5:14 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>>>
>>> kvm-unit-tests were adjusted to match bare metal behavior, but KVM
>>> itself was not doing what bare metal does; fix that.
>>>
>>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>>
>> Reported-by ?
>
> I found it myself while running the tests, was there a report too?
Perhaps it is in my mind. I thought that fixing a test is equivalent to a
bug report.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-07-05 13:47 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2019-07-05 12:14 [PATCH] KVM: LAPIC: ARBPRI is a reserved register for x2APIC Paolo Bonzini
2019-07-05 12:37 ` Liran Alon
2019-07-05 12:46 ` Paolo Bonzini
2019-07-05 13:37 ` Nadav Amit
2019-07-05 13:43 ` Paolo Bonzini
2019-07-05 13:47 ` Nadav Amit
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