[Xen-changelog] [xen master] viridian: introduce struct viridian_page

[p***@xen.org]

commit b8f0767b438bb00b3bddb58dd0bb6001cff29d23
Author: Paul Durrant <***@citrix.com>
AuthorDate: Fri Nov 9 11:40:12 2018 +0100
Commit: Jan Beulich <***@suse.com>
CommitDate: Fri Nov 9 11:40:12 2018 +0100

viridian: introduce struct viridian_page

The 'vp_assist' page is currently an example of a guest page which needs to
be kept mapped throughout the life-time of a guest, but there are other
such examples in the specifiction [1]. This patch therefore introduces a
generic 'viridian_page' type and converts the current vp_assist/apic_assist
related code to use it. Subsequent patches implementing other enlightments
can then also make use of it.

This patch also renames the 'vp_assist_pending' field in struct
hvm_viridian_vcpu_context to 'apic_assist_pending' to more accurately
reflect its meaning. The term 'vp_assist' applies to the whole page rather
than just the EOI-avoidance enlightenment. New versons of the specification
have defined data structures for other enlightenments within the same page.

No functional change.

[1] https://github.com/MicrosoftDocs/Virtualization-Documentation/raw/live/tlfs/Hypervisor%20Top%20Level%20Functional%20Specification%20v5.0C.pdf

Signed-off-by: Paul Durrant <***@citrix.com>
Reviewed-by: Roger Pau Monne <***@citrix.com>
Reviewed-by: Wei Liu <***@citrix.com>
---
tools/misc/xen-hvmctx.c | 4 +-
xen/arch/x86/hvm/viridian/private.h | 5 ++
xen/arch/x86/hvm/viridian/synic.c | 90 ++++++----------------------------
xen/arch/x86/hvm/viridian/viridian.c | 57 +++++++++++++++++++++
xen/include/asm-x86/hvm/viridian.h | 13 ++---
xen/include/public/arch-x86/hvm/save.h | 2 +-
6 files changed, 87 insertions(+), 84 deletions(-)

diff --git a/tools/misc/xen-hvmctx.c b/tools/misc/xen-hvmctx.c
index 823aa7d736..4f336a6cea 100644
--- a/tools/misc/xen-hvmctx.c
+++ b/tools/misc/xen-hvmctx.c
@@ -370,9 +370,9 @@ static void dump_viridian_vcpu(void)
{
HVM_SAVE_TYPE(VIRIDIAN_VCPU) p;
READ(p);
- printf(" VIRIDIAN_VCPU: vp_assist_msr 0x%llx, vp_assist_pending %s\n",
+ printf(" VIRIDIAN_VCPU: vp_assist_msr 0x%llx, apic_assist_pending %s\n",
(unsigned long long) p.vp_assist_msr,
- p.vp_assist_pending ? "true" : "false");
+ p.apic_assist_pending ? "true" : "false");
}

static void dump_vmce_vcpu(void)
diff --git a/xen/arch/x86/hvm/viridian/private.h b/xen/arch/x86/hvm/viridian/private.h
index a5e06f9866..398b22f12d 100644
--- a/xen/arch/x86/hvm/viridian/private.h
+++ b/xen/arch/x86/hvm/viridian/private.h
@@ -87,6 +87,11 @@ void viridian_time_save_domain_ctxt(
void viridian_time_load_domain_ctxt(
struct domain *d, const struct hvm_viridian_domain_context *ctxt);

+void viridian_dump_guest_page(const struct vcpu *v, const char *name,
+ const struct viridian_page *vp);
+void viridian_map_guest_page(struct vcpu *v, struct viridian_page *vp);
+void viridian_unmap_guest_page(struct viridian_page *vp);
+
#endif /* X86_HVM_VIRIDIAN_PRIVATE_H */

/*
diff --git a/xen/arch/x86/hvm/viridian/synic.c b/xen/arch/x86/hvm/viridian/synic.c
index d8d6f6e1c9..845029b568 100644
--- a/xen/arch/x86/hvm/viridian/synic.c
+++ b/xen/arch/x86/hvm/viridian/synic.c
@@ -22,73 +22,11 @@ typedef struct _HV_VIRTUAL_APIC_ASSIST
uint32_t reserved_zero:31;
} HV_VIRTUAL_APIC_ASSIST;

-union _HV_VP_ASSIST_PAGE
+typedef union _HV_VP_ASSIST_PAGE
{
HV_VIRTUAL_APIC_ASSIST ApicAssist;
uint8_t ReservedZBytePadding[PAGE_SIZE];
-};
-
-static void dump_vp_assist(const struct vcpu *v)
-{
- const union viridian_page_msr *va = &v->arch.hvm.viridian.vp_assist.msr;
-
- if ( !va->fields.enabled )
- return;
-
- printk(XENLOG_G_INFO "%pv: VIRIDIAN VP_ASSIST_PAGE: pfn: %lx\n",
- v, (unsigned long)va->fields.pfn);
-}
-
-static void initialize_vp_assist(struct vcpu *v)
-{
- struct domain *d = v->domain;
- unsigned long gmfn = v->arch.hvm.viridian.vp_assist.msr.fields.pfn;
- struct page_info *page = get_page_from_gfn(d, gmfn, NULL, P2M_ALLOC);
- HV_VP_ASSIST_PAGE *ptr;
-
- ASSERT(!v->arch.hvm.viridian.vp_assist.ptr);
-
- if ( !page )
- goto fail;
-
- if ( !get_page_type(page, PGT_writable_page) )
- {
- put_page(page);
- goto fail;
- }
-
- ptr = __map_domain_page_global(page);
- if ( !ptr )
- {
- put_page_and_type(page);
- goto fail;
- }
-
- clear_page(ptr);
-
- v->arch.hvm.viridian.vp_assist.ptr = ptr;
- return;
-
- fail:
- gdprintk(XENLOG_WARNING, "Bad GMFN %#"PRI_gfn" (MFN %#"PRI_mfn")\n",
- gmfn, mfn_x(page ? page_to_mfn(page) : INVALID_MFN));
-}
-
-static void teardown_vp_assist(struct vcpu *v)
-{
- HV_VP_ASSIST_PAGE *ptr = v->arch.hvm.viridian.vp_assist.ptr;
- struct page_info *page;
-
- if ( !ptr )
- return;
-
- v->arch.hvm.viridian.vp_assist.ptr = NULL;
-
- page = mfn_to_page(domain_page_map_to_mfn(ptr));
-
- unmap_domain_page_global(ptr);
- put_page_and_type(page);
-}
+} HV_VP_ASSIST_PAGE;

void viridian_apic_assist_set(struct vcpu *v)
{
@@ -102,10 +40,10 @@ void viridian_apic_assist_set(struct vcpu *v)
* wrong and the VM will most likely hang so force a crash now
* to make the problem clear.
*/
- if ( v->arch.hvm.viridian.vp_assist.pending )
+ if ( v->arch.hvm.viridian.apic_assist_pending )
domain_crash(v->domain);

- v->arch.hvm.viridian.vp_assist.pending = true;
+ v->arch.hvm.viridian.apic_assist_pending = true;
ptr->ApicAssist.no_eoi = 1;
}

@@ -116,11 +54,11 @@ bool viridian_apic_assist_completed(struct vcpu *v)
if ( !ptr )
return false;

- if ( v->arch.hvm.viridian.vp_assist.pending &&
+ if ( v->arch.hvm.viridian.apic_assist_pending &&
!ptr->ApicAssist.no_eoi )
{
/* An EOI has been avoided */
- v->arch.hvm.viridian.vp_assist.pending = false;
+ v->arch.hvm.viridian.apic_assist_pending = false;
return true;
}

@@ -135,7 +73,7 @@ void viridian_apic_assist_clear(struct vcpu *v)
return;

ptr->ApicAssist.no_eoi = 0;
- v->arch.hvm.viridian.vp_assist.pending = false;
+ v->arch.hvm.viridian.apic_assist_pending = false;
}

int viridian_synic_wrmsr(struct vcpu *v, uint32_t idx, uint64_t val)
@@ -161,11 +99,13 @@ int viridian_synic_wrmsr(struct vcpu *v, uint32_t idx, uint64_t val)
break;

case HV_X64_MSR_VP_ASSIST_PAGE:
- teardown_vp_assist(v); /* release any previous mapping */
+ /* release any previous mapping */
+ viridian_unmap_guest_page(&v->arch.hvm.viridian.vp_assist);
v->arch.hvm.viridian.vp_assist.msr.raw = val;
- dump_vp_assist(v);
+ viridian_dump_guest_page(v, "VP_ASSIST",
+ &v->arch.hvm.viridian.vp_assist);
if ( v->arch.hvm.viridian.vp_assist.msr.fields.enabled )
- initialize_vp_assist(v);
+ viridian_map_guest_page(v, &v->arch.hvm.viridian.vp_assist);
break;

default:
@@ -211,7 +151,7 @@ int viridian_synic_rdmsr(const struct vcpu *v, uint32_t idx, uint64_t *val)
void viridian_synic_save_vcpu_ctxt(const struct vcpu *v,
struct hvm_viridian_vcpu_context *ctxt)
{
- ctxt->vp_assist_pending = v->arch.hvm.viridian.vp_assist.pending;
+ ctxt->apic_assist_pending = v->arch.hvm.viridian.apic_assist_pending;
ctxt->vp_assist_msr = v->arch.hvm.viridian.vp_assist.msr.raw;
}

@@ -220,9 +160,9 @@ void viridian_synic_load_vcpu_ctxt(
{
v->arch.hvm.viridian.vp_assist.msr.raw = ctxt->vp_assist_msr;
if ( v->arch.hvm.viridian.vp_assist.msr.fields.enabled )
- initialize_vp_assist(v);
+ viridian_map_guest_page(v, &v->arch.hvm.viridian.vp_assist);

- v->arch.hvm.viridian.vp_assist.pending = !!ctxt->vp_assist_pending;
+ v->arch.hvm.viridian.apic_assist_pending = ctxt->apic_assist_pending;
}

/*
diff --git a/xen/arch/x86/hvm/viridian/viridian.c b/xen/arch/x86/hvm/viridian/viridian.c
index 8630bc7bb6..7d73f41de6 100644
--- a/xen/arch/x86/hvm/viridian/viridian.c
+++ b/xen/arch/x86/hvm/viridian/viridian.c
@@ -588,6 +588,63 @@ out:
return HVM_HCALL_completed;
}

+void viridian_dump_guest_page(const struct vcpu *v, const char *name,
+ const struct viridian_page *vp)
+{
+ if ( !vp->msr.fields.enabled )
+ return;
+
+ printk(XENLOG_G_INFO "%pv: VIRIDIAN %s: pfn: %lx\n",
+ v, name, (unsigned long)vp->msr.fields.pfn);
+}
+
+void viridian_map_guest_page(struct vcpu *v, struct viridian_page *vp)
+{
+ struct domain *d = v->domain;
+ unsigned long gmfn = vp->msr.fields.pfn;
+ struct page_info *page = get_page_from_gfn(d, gmfn, NULL, P2M_ALLOC);
+
+ ASSERT(!vp->ptr);
+
+ if ( !page )
+ goto fail;
+
+ if ( !get_page_type(page, PGT_writable_page) )
+ {
+ put_page(page);
+ goto fail;
+ }
+
+ vp->ptr = __map_domain_page_global(page);
+ if ( !vp->ptr )
+ {
+ put_page_and_type(page);
+ goto fail;
+ }
+
+ clear_page(vp->ptr);
+ return;
+
+ fail:
+ gdprintk(XENLOG_WARNING, "Bad GMFN %#"PRI_gfn" (MFN %#"PRI_mfn")\n",
+ gmfn, mfn_x(page ? page_to_mfn(page) : INVALID_MFN));
+}
+
+void viridian_unmap_guest_page(struct viridian_page *vp)
+{
+ struct page_info *page;
+
+ if ( !vp->ptr )
+ return;
+
+ page = mfn_to_page(domain_page_map_to_mfn(vp->ptr));
+
+ unmap_domain_page_global(vp->ptr);
+ vp->ptr = NULL;
+
+ put_page_and_type(page);
+}
+
static int viridian_save_domain_ctxt(struct vcpu *v,
hvm_domain_context_t *h)
{
diff --git a/xen/include/asm-x86/hvm/viridian.h b/xen/include/asm-x86/hvm/viridian.h
index 22f14a526e..ec5ef8d3f9 100644
--- a/xen/include/asm-x86/hvm/viridian.h
+++ b/xen/include/asm-x86/hvm/viridian.h
@@ -20,15 +20,16 @@ union viridian_page_msr
} fields;
};

-typedef union _HV_VP_ASSIST_PAGE HV_VP_ASSIST_PAGE;
+struct viridian_page
+{
+ union viridian_page_msr msr;
+ void *ptr;
+};

struct viridian_vcpu
{
- struct {
- union viridian_page_msr msr;
- HV_VP_ASSIST_PAGE *ptr;
- bool pending;
- } vp_assist;
+ struct viridian_page vp_assist;
+ bool apic_assist_pending;
uint64_t crash_param[5];
};

diff --git a/xen/include/public/arch-x86/hvm/save.h b/xen/include/public/arch-x86/hvm/save.h
index 4691d4d4aa..80e762c335 100644
--- a/xen/include/public/arch-x86/hvm/save.h
+++ b/xen/include/public/arch-x86/hvm/save.h
@@ -600,7 +600,7 @@ DECLARE_HVM_SAVE_TYPE(VIRIDIAN_DOMAIN, 15, struct hvm_viridian_domain_context);

struct hvm_viridian_vcpu_context {
uint64_t vp_assist_msr;
- uint8_t vp_assist_pending;
+ uint8_t apic_assist_pending;
uint8_t _pad[7];
};

--
generated by git-patchbot for /home/xen/git/xen.git#master