* [PATCH] kvm: document lapic regs field
@ 2012-05-23 16:16 Michael S. Tsirkin
2012-06-01 22:34 ` Marcelo Tosatti
0 siblings, 1 reply; 2+ messages in thread
From: Michael S. Tsirkin @ 2012-05-23 16:16 UTC (permalink / raw)
To: kvm; +Cc: Avi Kivity, Marcelo Tosatti
The logic in find_highest_vector looks
strange until you realize the reason for the
weird memory layout, which is because this is
what the CPU microcode expects.
Add a comment so this stops tripping people up.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
arch/x86/kvm/lapic.h | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 41c62c7..1d1ec08 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -15,6 +15,11 @@ struct kvm_lapic {
bool irr_pending;
s16 isr_count;
int isr_cache;
+ /**
+ * APIC register page. The layout matches the register layout seen by
+ * the guest 1:1, because it is accessed by the vmx microcode.
+ * Note: Only one register, the TPR, is used by the microcode.
+ */
void *regs;
gpa_t vapic_addr;
struct page *vapic_page;
--
MST
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] kvm: document lapic regs field
2012-05-23 16:16 [PATCH] kvm: document lapic regs field Michael S. Tsirkin
@ 2012-06-01 22:34 ` Marcelo Tosatti
0 siblings, 0 replies; 2+ messages in thread
From: Marcelo Tosatti @ 2012-06-01 22:34 UTC (permalink / raw)
To: Michael S. Tsirkin; +Cc: kvm, Avi Kivity
On Wed, May 23, 2012 at 07:16:14PM +0300, Michael S. Tsirkin wrote:
> The logic in find_highest_vector looks
> strange until you realize the reason for the
> weird memory layout, which is because this is
> what the CPU microcode expects.
>
> Add a comment so this stops tripping people up.
>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> arch/x86/kvm/lapic.h | 5 +++++
> 1 files changed, 5 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
> index 41c62c7..1d1ec08 100644
> --- a/arch/x86/kvm/lapic.h
> +++ b/arch/x86/kvm/lapic.h
> @@ -15,6 +15,11 @@ struct kvm_lapic {
> bool irr_pending;
> s16 isr_count;
> int isr_cache;
Wrong branch.
^ permalink raw reply [flat|nested] 2+ messages in thread
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