On Wed, Aug 01, 2012 at 04:19:01PM +0530, Raghavendra K T wrote: > On 08/01/2012 08:37 AM, Marcelo Tosatti wrote: > >On Tue, Jul 24, 2012 at 02:23:59PM +0530, Raghavendra K T wrote: > >>From: Raghavendra K T<raghavendra.kt@xxxxxxxxxxxxxxxxxx> > >> > >>Thanks Alex for KVM_HC_FEATURES inputs and Jan for VAPIC_POLL_IRQ, > >>and Peter (HPA) for suggesting hypercall ABI addition. > >> > >>Signed-off-by: Raghavendra K T<raghavendra.kt@xxxxxxxxxxxxxxxxxx> > >>--- > >>Please have a closer look at Hypercall ABI newly added > >> > >>Changes since last post: > >> - Added hypercall ABI (Peter) > >> - made KVM_HC_VAPIC_POLL_IRQ active explicitly (Randy) > >> > >>TODO: We need to add history details of each hypercall as suggested by HPA, > >>which I could not trace easily. Hope it is easy for hypercall authors > >> > >> Documentation/virtual/hypercalls.txt | 71 ++++++++++++++++++++++++++++++++++ > >> 1 files changed, 71 insertions(+), 0 deletions(-) > >> create mode 100644 Documentation/virtual/hypercalls.txt > >> > >>diff --git a/Documentation/virtual/hypercalls.txt b/Documentation/virtual/hypercalls.txt > >>new file mode 100644 > >>index 0000000..caffc08 > >>--- /dev/null > >>+++ b/Documentation/virtual/hypercalls.txt > >>@@ -0,0 +1,71 @@ > >>+Hypercall ABI: > >>+============= > >>+A brief look at calling conventions of X86, S390 and PPC > >>+X86: > >>+ KVM Hypercalls have a three-byte sequence of either the vmrun or the vmmrun > >>+ instruction. The hypervisor can replace it with instructions that are > >>+ guaranteed to be supported. > > > >vmcall. > > How is this: > KVM Hypercalls have a three-byte sequence of vmcall instruction. But > The hypervisor can replace it with the instructions that are guaranteed > to be supported. > > (Related question: Is it not that vmcall instruction is patched by 0f > 01 09 vmmcall instruction sequence for amd?. Yes, it is. Linux guest binary contains the Intel vmcall instruction, which is patched on AMD to vmmcall. > So I think we need to > change documentation I referred from arch/x86/include/asm/kvm_para.h. > It should be vmcall / vmmcall instead of vmrun and vmmrun) Yes. > >>+ > >>+ Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively. > >>+ The hypercall number should be placed in rax and the return value will be > >>+ placed in rax. No other registers will be clobbered unless explicitly stated > >>+ by the particular hypercall. > > > >It depends on the hypercall. It happens that current hypercalls use > >the four registers, but its not an ABI (hyper-v hypercalls uses r8, for example). > > > > Okay, agree. I did not know about hyper-v. Above one is for X86 and > KVM (and not X86 / hyper-v). So I should remove ABI and probably say, Just say "Linux x86 Hypercall", yeah. > KVM x86 Hypercall > ================== > Up to four arguments may be passed in rbx, rcx, rdx, and rsi > respectively. The hypercall number should be placed in rax and the > return value will be placed in rax. No other registers will be > clobbered unless explicitly stated by the particular hypercall. > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
