| Message ID | 20200207113958.7320-22-borntraeger@de.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: s390: Add support for protected VMs | expand |
On 07/02/2020 12.39, Christian Borntraeger wrote: > From: Claudio Imbrenda <imbrenda@linux.ibm.com> > > The current code tries to first pin shared pages, if that fails (e.g. > because the page is not shared) it will export them. For shared pages > this means that we get a new intercept telling us that the guest is > unsharing that page. We will make the page secure at that point in time > and revoke the host access. This is synchronized with other host events, > e.g. the code will wait until host I/O has finished. > > Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> > [borntraeger@de.ibm.com: patch merging, splitting, fixing] > Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> > --- > arch/s390/kvm/intercept.c | 24 ++++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > > diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c > index 2a966dc52611..e155389a4a66 100644 > --- a/arch/s390/kvm/intercept.c > +++ b/arch/s390/kvm/intercept.c > @@ -16,6 +16,7 @@ > #include <asm/asm-offsets.h> > #include <asm/irq.h> > #include <asm/sysinfo.h> > +#include <asm/uv.h> > > #include "kvm-s390.h" > #include "gaccess.h" > @@ -484,12 +485,35 @@ static int handle_pv_sclp(struct kvm_vcpu *vcpu) > return 0; > } > > +static int handle_pv_uvc(struct kvm_vcpu *vcpu) > +{ > + struct uv_cb_share *guest_uvcb = (void *)vcpu->arch.sie_block->sidad; > + struct uv_cb_cts uvcb = { > + .header.cmd = UVC_CMD_UNPIN_PAGE_SHARED, > + .header.len = sizeof(uvcb), > + .guest_handle = kvm_s390_pv_handle(vcpu->kvm), > + .gaddr = guest_uvcb->paddr, > + }; > + int rc; > + > + if (guest_uvcb->header.cmd != UVC_CMD_REMOVE_SHARED_ACCESS) { > + WARN_ONCE(1, "Unexpected UVC 0x%x!\n", guest_uvcb->header.cmd); Is there a way to signal the failed command to the guest, too? Thomas > + return 0; > + } > + rc = uv_make_secure(vcpu->arch.gmap, uvcb.gaddr, &uvcb); > + if (rc == -EINVAL && uvcb.header.rc == 0x104) > + return 0; > + return rc; > +} > + > static int handle_pv_notification(struct kvm_vcpu *vcpu) > { > if (vcpu->arch.sie_block->ipa == 0xb210) > return handle_pv_spx(vcpu); > if (vcpu->arch.sie_block->ipa == 0xb220) > return handle_pv_sclp(vcpu); > + if (vcpu->arch.sie_block->ipa == 0xb9a4) > + return handle_pv_uvc(vcpu); > > return handle_instruction(vcpu); > } >
On Mon, 10 Feb 2020 15:58:11 +0100 Thomas Huth <thuth@redhat.com> wrote: > On 07/02/2020 12.39, Christian Borntraeger wrote: > > From: Claudio Imbrenda <imbrenda@linux.ibm.com> > > > > The current code tries to first pin shared pages, if that fails (e.g. > > because the page is not shared) it will export them. For shared pages > > this means that we get a new intercept telling us that the guest is > > unsharing that page. We will make the page secure at that point in time > > and revoke the host access. This is synchronized with other host events, > > e.g. the code will wait until host I/O has finished. > > > > Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> > > [borntraeger@de.ibm.com: patch merging, splitting, fixing] > > Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> > > --- > > arch/s390/kvm/intercept.c | 24 ++++++++++++++++++++++++ > > 1 file changed, 24 insertions(+) > > > > diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c > > index 2a966dc52611..e155389a4a66 100644 > > --- a/arch/s390/kvm/intercept.c > > +++ b/arch/s390/kvm/intercept.c > > @@ -16,6 +16,7 @@ > > #include <asm/asm-offsets.h> > > #include <asm/irq.h> > > #include <asm/sysinfo.h> > > +#include <asm/uv.h> > > > > #include "kvm-s390.h" > > #include "gaccess.h" > > @@ -484,12 +485,35 @@ static int handle_pv_sclp(struct kvm_vcpu *vcpu) > > return 0; > > } > > > > +static int handle_pv_uvc(struct kvm_vcpu *vcpu) > > +{ > > + struct uv_cb_share *guest_uvcb = (void *)vcpu->arch.sie_block->sidad; > > + struct uv_cb_cts uvcb = { > > + .header.cmd = UVC_CMD_UNPIN_PAGE_SHARED, > > + .header.len = sizeof(uvcb), > > + .guest_handle = kvm_s390_pv_handle(vcpu->kvm), > > + .gaddr = guest_uvcb->paddr, > > + }; > > + int rc; > > + > > + if (guest_uvcb->header.cmd != UVC_CMD_REMOVE_SHARED_ACCESS) { > > + WARN_ONCE(1, "Unexpected UVC 0x%x!\n", guest_uvcb->header.cmd); > > Is there a way to signal the failed command to the guest, too? I'm wondering at which layer the actual problem occurs here. Is it because a (new) command was not interpreted or rejected by the ultravisor so that it ended up being handled by the hypervisor? If so, what should the guest know? > > Thomas > > > > + return 0; > > + } > > + rc = uv_make_secure(vcpu->arch.gmap, uvcb.gaddr, &uvcb); > > + if (rc == -EINVAL && uvcb.header.rc == 0x104) This wants a comment. > > + return 0; > > + return rc; > > +} > > + > > static int handle_pv_notification(struct kvm_vcpu *vcpu) > > { > > if (vcpu->arch.sie_block->ipa == 0xb210) > > return handle_pv_spx(vcpu); > > if (vcpu->arch.sie_block->ipa == 0xb220) > > return handle_pv_sclp(vcpu); > > + if (vcpu->arch.sie_block->ipa == 0xb9a4) > > + return handle_pv_uvc(vcpu); Is it defined by the architecture what the possible commands are for which the hypervisor may get control? If we get something unexpected, is returning 0 the right strategy? > > > > return handle_instruction(vcpu); > > } > > >
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c index 2a966dc52611..e155389a4a66 100644 --- a/arch/s390/kvm/intercept.c +++ b/arch/s390/kvm/intercept.c @@ -16,6 +16,7 @@ #include <asm/asm-offsets.h> #include <asm/irq.h> #include <asm/sysinfo.h> +#include <asm/uv.h> #include "kvm-s390.h" #include "gaccess.h" @@ -484,12 +485,35 @@ static int handle_pv_sclp(struct kvm_vcpu *vcpu) return 0; } +static int handle_pv_uvc(struct kvm_vcpu *vcpu) +{ + struct uv_cb_share *guest_uvcb = (void *)vcpu->arch.sie_block->sidad; + struct uv_cb_cts uvcb = { + .header.cmd = UVC_CMD_UNPIN_PAGE_SHARED, + .header.len = sizeof(uvcb), + .guest_handle = kvm_s390_pv_handle(vcpu->kvm), + .gaddr = guest_uvcb->paddr, + }; + int rc; + + if (guest_uvcb->header.cmd != UVC_CMD_REMOVE_SHARED_ACCESS) { + WARN_ONCE(1, "Unexpected UVC 0x%x!\n", guest_uvcb->header.cmd); + return 0; + } + rc = uv_make_secure(vcpu->arch.gmap, uvcb.gaddr, &uvcb); + if (rc == -EINVAL && uvcb.header.rc == 0x104) + return 0; + return rc; +} + static int handle_pv_notification(struct kvm_vcpu *vcpu) { if (vcpu->arch.sie_block->ipa == 0xb210) return handle_pv_spx(vcpu); if (vcpu->arch.sie_block->ipa == 0xb220) return handle_pv_sclp(vcpu); + if (vcpu->arch.sie_block->ipa == 0xb9a4) + return handle_pv_uvc(vcpu); return handle_instruction(vcpu); }