| Message ID | 1455821530-4263-5-git-send-email-david.vrabel@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 18/02/16 18:52, David Vrabel wrote: > diff --git a/xen/arch/x86/hvm/viridian.c b/xen/arch/x86/hvm/viridian.c > index 6bd844b..fb9f044 100644 > --- a/xen/arch/x86/hvm/viridian.c > +++ b/xen/arch/x86/hvm/viridian.c > @@ -148,6 +148,30 @@ static void dump_guest_os_id(const struct domain *d) > goi->fields.service_pack, goi->fields.build_number); > } > > +static void set_guest_os_id(struct domain *d, uint64_t val) > +{ > + const union viridian_guest_os_id *goi; > + > + d->arch.hvm_domain.viridian.guest_os_id.raw = val; > + goi = &d->arch.hvm_domain.viridian.guest_os_id; > + > + /* > + * Microsoft Windows only saves the lower 32-bits of FIP/FDP and > + * can get upset if the selectors are not saved/restored by the > + * hypervisor. > + * > + * Only do this if the FIP width is not in auto-mode, so this > + * heuristic can be overriden by the toolstack. > + */ > + if ( !d->arch.x87_fip_width ) > + { > + if ( goi->fields.vendor == 1 && goi->fields.os == 4 ) Are there any named parameters we could use here? In principle, Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> (allowing for the potential change of x86_fip_width per the discussion on patch 3). > + d->arch.x87_fip_width = 4; > + } > + > + dump_guest_os_id(d); > +} > + > static void dump_hypercall(const struct domain *d) > { > const union viridian_hypercall_gpa *hg;
>>> On 18.02.16 at 19:52, <david.vrabel@citrix.com> wrote: > --- a/xen/arch/x86/hvm/viridian.c > +++ b/xen/arch/x86/hvm/viridian.c > @@ -148,6 +148,30 @@ static void dump_guest_os_id(const struct domain *d) > goi->fields.service_pack, goi->fields.build_number); > } > > +static void set_guest_os_id(struct domain *d, uint64_t val) > +{ > + const union viridian_guest_os_id *goi; > + > + d->arch.hvm_domain.viridian.guest_os_id.raw = val; > + goi = &d->arch.hvm_domain.viridian.guest_os_id; Please flip the two lines and use goi also for the assignment of val. Jan
diff --git a/xen/arch/x86/hvm/viridian.c b/xen/arch/x86/hvm/viridian.c index 6bd844b..fb9f044 100644 --- a/xen/arch/x86/hvm/viridian.c +++ b/xen/arch/x86/hvm/viridian.c @@ -148,6 +148,30 @@ static void dump_guest_os_id(const struct domain *d) goi->fields.service_pack, goi->fields.build_number); } +static void set_guest_os_id(struct domain *d, uint64_t val) +{ + const union viridian_guest_os_id *goi; + + d->arch.hvm_domain.viridian.guest_os_id.raw = val; + goi = &d->arch.hvm_domain.viridian.guest_os_id; + + /* + * Microsoft Windows only saves the lower 32-bits of FIP/FDP and + * can get upset if the selectors are not saved/restored by the + * hypervisor. + * + * Only do this if the FIP width is not in auto-mode, so this + * heuristic can be overriden by the toolstack. + */ + if ( !d->arch.x87_fip_width ) + { + if ( goi->fields.vendor == 1 && goi->fields.os == 4 ) + d->arch.x87_fip_width = 4; + } + + dump_guest_os_id(d); +} + static void dump_hypercall(const struct domain *d) { const union viridian_hypercall_gpa *hg; @@ -334,8 +358,7 @@ int wrmsr_viridian_regs(uint32_t idx, uint64_t val) { case VIRIDIAN_MSR_GUEST_OS_ID: perfc_incr(mshv_wrmsr_osid); - d->arch.hvm_domain.viridian.guest_os_id.raw = val; - dump_guest_os_id(d); + set_guest_os_id(d, val); break; case VIRIDIAN_MSR_HYPERCALL:
Microsoft Windows always uses a 32-bit FPU state save/restore and expects the FCS/FDS to be saved/restored. Ensure that for these guests, the hypervisor does 32-bit save/restore to preserve FCS/FDS. These guests are identified by the write to the Guest OS ID MSR. This fixes an 0x3D BugCheck when running the Driver Verifier in 64-bit Windows. This BugCheck occurs because a context switch would clear FCS/FDS and Driver Verifier would assert because the FPU state changed. We only set FIP width if it is still in auto-mode, to allow the toolstack to override if necessary. Signed-off-by: David Vrabel <david.vrabel@citrix.com> --- xen/arch/x86/hvm/viridian.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-)