| Message ID | 20230201143148.1744093-50-dwmw2@infradead.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Xen HVM support under KVM | expand |
On 01/02/2023 14:31, David Woodhouse wrote: > From: Joao Martins <joao.m.martins@oracle.com> > > Which is used to fetch xenstore PFN and port to be used > by the guest. This is preallocated by the toolstack when > guest will just read those and use it straight away. > > Signed-off-by: Joao Martins <joao.m.martins@oracle.com> > Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> > --- > target/i386/kvm/xen-emu.c | 39 +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 39 insertions(+) > > diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c > index 75e62bc02f..3d6ea7ca98 100644 > --- a/target/i386/kvm/xen-emu.c > +++ b/target/i386/kvm/xen-emu.c > @@ -762,6 +762,42 @@ out: > return true; > } > > +static bool handle_get_param(struct kvm_xen_exit *exit, X86CPU *cpu, > + uint64_t arg) > +{ > + CPUState *cs = CPU(cpu); > + struct xen_hvm_param hp; > + int err = 0; > + > + /* No need for 32/64 compat handling */ > + qemu_build_assert(sizeof(hp) == 16); > + > + if (kvm_copy_from_gva(cs, arg, &hp, sizeof(hp))) { > + err = -EFAULT; > + goto out; > + } > + > + if (hp.domid != DOMID_SELF && hp.domid != xen_domid) { > + err = -ESRCH; > + goto out; > + } > + > + switch (hp.index) { > + case HVM_PARAM_STORE_PFN: > + hp.value = XEN_SPECIAL_PFN(XENSTORE); Reviewed-by: Paul Durrant <paul@xen.org> ... but this reminds me... I don't think you have code to seed the grant table in any of the patches. It is guest ABI that the XenStore PFN is in entry 1 of the grant table. > + break; > + default: > + return false; > + } > + > + if (kvm_copy_to_gva(cs, arg, &hp, sizeof(hp))) { > + err = -EFAULT; > + } > +out: > + exit->u.hcall.result = err; > + return true; > +} > + > static int kvm_xen_hcall_evtchn_upcall_vector(struct kvm_xen_exit *exit, > X86CPU *cpu, uint64_t arg) > { > @@ -806,6 +842,9 @@ static bool kvm_xen_hcall_hvm_op(struct kvm_xen_exit *exit, X86CPU *cpu, > case HVMOP_set_param: > return handle_set_param(exit, cpu, arg); > > + case HVMOP_get_param: > + return handle_get_param(exit, cpu, arg); > + > default: > return false; > }
On 14 February 2023 16:47:13 CET, Paul Durrant <xadimgnik@gmail.com> wrote: >On 01/02/2023 14:31, David Woodhouse wrote: >> From: Joao Martins <joao.m.martins@oracle.com> >> >> Which is used to fetch xenstore PFN and port to be used >> by the guest. This is preallocated by the toolstack when >> guest will just read those and use it straight away. >> >> Signed-off-by: Joao Martins <joao.m.martins@oracle.com> >> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> >> --- >> target/i386/kvm/xen-emu.c | 39 +++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 39 insertions(+) >> >> diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c >> index 75e62bc02f..3d6ea7ca98 100644 >> --- a/target/i386/kvm/xen-emu.c >> +++ b/target/i386/kvm/xen-emu.c >> @@ -762,6 +762,42 @@ out: >> return true; >> } >> +static bool handle_get_param(struct kvm_xen_exit *exit, X86CPU *cpu, >> + uint64_t arg) >> +{ >> + CPUState *cs = CPU(cpu); >> + struct xen_hvm_param hp; >> + int err = 0; >> + >> + /* No need for 32/64 compat handling */ >> + qemu_build_assert(sizeof(hp) == 16); >> + >> + if (kvm_copy_from_gva(cs, arg, &hp, sizeof(hp))) { >> + err = -EFAULT; >> + goto out; >> + } >> + >> + if (hp.domid != DOMID_SELF && hp.domid != xen_domid) { >> + err = -ESRCH; >> + goto out; >> + } >> + >> + switch (hp.index) { >> + case HVM_PARAM_STORE_PFN: >> + hp.value = XEN_SPECIAL_PFN(XENSTORE); > >Reviewed-by: Paul Durrant <paul@xen.org> > >... but this reminds me... I don't think you have code to seed the grant table in any of the patches. It is guest ABI that the XenStore PFN is in entry 1 of the grant table. It's in there somewhere, perhaps in "phase 2" where we actually add a real XenStore rather than this sequence of 59 (and counting). I even made XenStore map the grant (not that it actually *uses* the address it gets back).
diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c index 75e62bc02f..3d6ea7ca98 100644 --- a/target/i386/kvm/xen-emu.c +++ b/target/i386/kvm/xen-emu.c @@ -762,6 +762,42 @@ out: return true; } +static bool handle_get_param(struct kvm_xen_exit *exit, X86CPU *cpu, + uint64_t arg) +{ + CPUState *cs = CPU(cpu); + struct xen_hvm_param hp; + int err = 0; + + /* No need for 32/64 compat handling */ + qemu_build_assert(sizeof(hp) == 16); + + if (kvm_copy_from_gva(cs, arg, &hp, sizeof(hp))) { + err = -EFAULT; + goto out; + } + + if (hp.domid != DOMID_SELF && hp.domid != xen_domid) { + err = -ESRCH; + goto out; + } + + switch (hp.index) { + case HVM_PARAM_STORE_PFN: + hp.value = XEN_SPECIAL_PFN(XENSTORE); + break; + default: + return false; + } + + if (kvm_copy_to_gva(cs, arg, &hp, sizeof(hp))) { + err = -EFAULT; + } +out: + exit->u.hcall.result = err; + return true; +} + static int kvm_xen_hcall_evtchn_upcall_vector(struct kvm_xen_exit *exit, X86CPU *cpu, uint64_t arg) { @@ -806,6 +842,9 @@ static bool kvm_xen_hcall_hvm_op(struct kvm_xen_exit *exit, X86CPU *cpu, case HVMOP_set_param: return handle_set_param(exit, cpu, arg); + case HVMOP_get_param: + return handle_get_param(exit, cpu, arg); + default: return false; }