On Thu, Feb 21, 2019 at 08:56:06PM +0000, Joao Martins wrote: > On 2/21/19 6:29 PM, Sean Christopherson wrote: > > On Wed, Feb 20, 2019 at 08:15:32PM +0000, Joao Martins wrote: > >> Add a new exit reason for emulator to handle Xen hypercalls. > >> Albeit these are injected only if guest has initialized the Xen > >> hypercall page - the hypercall is just a convenience but one > >> that is done by pretty much all guests. Hence if the guest > >> sets the hypercall page, we assume a Xen guest is going to > >> be set up. > >> > >> Emulator will then panic with: > >> > >> KVM: unknown exit reason 28 > >> RAX=0000000000000011 RBX=ffffffff81e03e94 RCX=0000000040000000 > >> RDX=0000000000000000 > >> RSI=ffffffff81e03e70 RDI=0000000000000006 RBP=ffffffff81e03e90 > >> RSP=ffffffff81e03e68 > >> R8 =73726576206e6558 R9 =ffffffff81e03e90 R10=ffffffff81e03e94 > >> R11=2e362e34206e6f69 > >> R12=0000000040000004 R13=ffffffff81e03e8c R14=ffffffff81e03e88 > >> R15=0000000000000000 > >> RIP=ffffffff81001228 RFL=00000082 [--S----] CPL=0 II=0 A20=1 SMM=0 HLT=0 > >> ES =0000 0000000000000000 ffffffff 00c00000 > >> CS =0010 0000000000000000 ffffffff 00a09b00 DPL=0 CS64 [-RA] > >> SS =0000 0000000000000000 ffffffff 00c00000 > >> DS =0000 0000000000000000 ffffffff 00c00000 > >> FS =0000 0000000000000000 ffffffff 00c00000 > >> GS =0000 ffffffff81f34000 ffffffff 00c00000 > >> LDT=0000 0000000000000000 ffffffff 00c00000 > >> TR =0020 0000000000000000 00000fff 00808b00 DPL=0 TSS64-busy > >> GDT= ffffffff81f3c000 0000007f > >> IDT= ffffffff83265000 00000fff > >> CR0=80050033 CR2=ffff880001fa6ff8 CR3=0000000001fa6000 CR4=000406a0 > >> DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 > >> DR3=0000000000000000 > >> DR6=00000000ffff0ff0 DR7=0000000000000400 > >> EFER=0000000000000d01 > >> Code=cc cc cc cc cc cc cc cc cc cc cc cc b8 11 00 00 00 0f 01 c1 <c3> cc > >> cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc b8 12 > >> 00 00 00 0f > >> > >> Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx> > >> --- > >> arch/x86/include/asm/kvm_host.h | 13 +++++++ > >> arch/x86/kvm/Makefile | 2 +- > >> arch/x86/kvm/trace.h | 33 +++++++++++++++++ > >> arch/x86/kvm/x86.c | 12 +++++++ > >> arch/x86/kvm/xen.c | 79 +++++++++++++++++++++++++++++++++++++++++ > >> arch/x86/kvm/xen.h | 10 ++++++ > >> include/uapi/linux/kvm.h | 17 ++++++++- > >> 7 files changed, 164 insertions(+), 2 deletions(-) > >> create mode 100644 arch/x86/kvm/xen.c > >> create mode 100644 arch/x86/kvm/xen.h > > > > ... > > > >> diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile > >> index 31ecf7a76d5a..2b46c93c9380 100644 > >> --- a/arch/x86/kvm/Makefile > >> +++ b/arch/x86/kvm/Makefile > >> @@ -10,7 +10,7 @@ kvm-$(CONFIG_KVM_ASYNC_PF) += $(KVM)/async_pf.o > >> > >> kvm-y += x86.o mmu.o emulate.o i8259.o irq.o lapic.o \ > >> i8254.o ioapic.o irq_comm.o cpuid.o pmu.o mtrr.o \ > >> - hyperv.o page_track.o debugfs.o > >> + hyperv.o xen.o page_track.o debugfs.o > > > > Can this be wrapped in a config? Or even better, as a loadable module? > > Turning that into a loadable module might be a little trickier, but I think it > is doable if that's what folks/maintainers would prefer. > > The Xen addition follows the same structure as Hyper-V in kvm (what you suggest > here is probably applicable for both). i.e. there's some Xen specific routines > for vm/vcpu init/teardown, and timer handling. We would have to place some of > those functions into a struct that gets registered at modinit. Huh. I never really hooked at the Hyper-V code, for some reason I always assumed it was only related to running KVM on Hyper-V. I agree that this extra hurdle only makes sense if it's also applied to Hyper-V.
