[Xen-changelog] [xen staging] x86/altp2m: propagate ept.ad changes to all active altp2ms

[p***@xen.org]

commit 303cee10a677dd8c5c130e50ddad6517c12e0276
Author: Razvan Cojocaru <***@bitdefender.com>
AuthorDate: Thu Nov 15 13:35:08 2018 +0100
Commit: Jan Beulich <***@suse.com>
CommitDate: Thu Nov 15 13:35:08 2018 +0100

x86/altp2m: propagate ept.ad changes to all active altp2ms

This patch is a pre-requisite for fixing the logdirty VGA issue
(display freezes when switching to a new altp2m view early in a
domain's lifetime).

The new ept_set_ad_sync() function has been added to update all
active altp2ms' ept.ad. New altp2ms will inherit the hostp2m's
ept.ad value.

The p2m_{en,dis}able_hardware_log_dirty() hostp2m locking has
been moved to the new ept_{en,dis}able_hardware_log_dirty()
functions as part of the code refactoring, while locks for the
individual altp2ms are taken in ept_set_ad_sync() (called by
ept_{en,dis}able_pml()).

Suggested-by: George Dunlap <***@citrix.com>
Signed-off-by: Razvan Cojocaru <***@bitdefender.com>
Tested-by: Tamas K Lengyel <***@tklengyel.com>
Acked-by: George Dunlap <***@citrix.com>
Reviewed-by: Kevin Tian <***@intel.com>
---
xen/arch/x86/mm/p2m-ept.c | 57 +++++++++++++++++++++++++++++++++++++++++++----
xen/arch/x86/mm/p2m.c | 8 -------
2 files changed, 53 insertions(+), 12 deletions(-)

diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
index 407e299e50..fabcd06f07 100644
--- a/xen/arch/x86/mm/p2m-ept.c
+++ b/xen/arch/x86/mm/p2m-ept.c
@@ -17,6 +17,7 @@

#include <xen/domain_page.h>
#include <xen/sched.h>
+#include <asm/altp2m.h>
#include <asm/current.h>
#include <asm/paging.h>
#include <asm/types.h>
@@ -1222,6 +1223,34 @@ static void ept_tlb_flush(struct p2m_domain *p2m)
ept_sync_domain_mask(p2m, p2m->domain->dirty_cpumask);
}

+static void ept_set_ad_sync(struct domain *d, bool value)
+{
+ struct p2m_domain *hostp2m = p2m_get_hostp2m(d);
+
+ ASSERT(p2m_locked_by_me(hostp2m));
+
+ hostp2m->ept.ad = value;
+
+ if ( unlikely(altp2m_active(d)) )
+ {
+ unsigned int i;
+
+ for ( i = 0; i < MAX_ALTP2M; i++ )
+ {
+ struct p2m_domain *p2m;
+
+ if ( d->arch.altp2m_eptp[i] == mfn_x(INVALID_MFN) )
+ continue;
+
+ p2m = d->arch.altp2m_p2m[i];
+
+ p2m_lock(p2m);
+ p2m->ept.ad = value;
+ p2m_unlock(p2m);
+ }
+ }
+}
+
static void ept_enable_pml(struct p2m_domain *p2m)
{
/* Domain must have been paused */
@@ -1236,7 +1265,7 @@ static void ept_enable_pml(struct p2m_domain *p2m)
return;

/* Enable EPT A/D bit for PML */
- p2m->ept.ad = 1;
+ ept_set_ad_sync(p2m->domain, true);
vmx_domain_update_eptp(p2m->domain);
}

@@ -1248,10 +1277,28 @@ static void ept_disable_pml(struct p2m_domain *p2m)
vmx_domain_disable_pml(p2m->domain);

/* Disable EPT A/D bit */
- p2m->ept.ad = 0;
+ ept_set_ad_sync(p2m->domain, false);
vmx_domain_update_eptp(p2m->domain);
}

+static void ept_enable_hardware_log_dirty(struct p2m_domain *p2m)
+{
+ struct p2m_domain *hostp2m = p2m_get_hostp2m(p2m->domain);
+
+ p2m_lock(hostp2m);
+ ept_enable_pml(hostp2m);
+ p2m_unlock(hostp2m);
+}
+
+static void ept_disable_hardware_log_dirty(struct p2m_domain *p2m)
+{
+ struct p2m_domain *hostp2m = p2m_get_hostp2m(p2m->domain);
+
+ p2m_lock(hostp2m);
+ ept_disable_pml(hostp2m);
+ p2m_unlock(hostp2m);
+}
+
static void ept_flush_pml_buffers(struct p2m_domain *p2m)
{
/* Domain must have been paused */
@@ -1281,8 +1328,8 @@ int ept_p2m_init(struct p2m_domain *p2m)

if ( cpu_has_vmx_pml )
{
- p2m->enable_hardware_log_dirty = ept_enable_pml;
- p2m->disable_hardware_log_dirty = ept_disable_pml;
+ p2m->enable_hardware_log_dirty = ept_enable_hardware_log_dirty;
+ p2m->disable_hardware_log_dirty = ept_disable_hardware_log_dirty;
p2m->flush_hardware_cached_dirty = ept_flush_pml_buffers;
}

@@ -1390,8 +1437,10 @@ void setup_ept_dump(void)
void p2m_init_altp2m_ept(struct domain *d, unsigned int i)
{
struct p2m_domain *p2m = d->arch.altp2m_p2m[i];
+ struct p2m_domain *hostp2m = p2m_get_hostp2m(d);
struct ept_data *ept;

+ p2m->ept.ad = hostp2m->ept.ad;
p2m->min_remapped_gfn = gfn_x(INVALID_GFN);
p2m->max_remapped_gfn = 0;
ept = &p2m->ept;
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 4bdc5e34e0..6a1abb6df5 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -360,11 +360,7 @@ void p2m_enable_hardware_log_dirty(struct domain *d)
struct p2m_domain *p2m = p2m_get_hostp2m(d);

if ( p2m->enable_hardware_log_dirty )
- {
- p2m_lock(p2m);
p2m->enable_hardware_log_dirty(p2m);
- p2m_unlock(p2m);
- }
}

void p2m_disable_hardware_log_dirty(struct domain *d)
@@ -372,11 +368,7 @@ void p2m_disable_hardware_log_dirty(struct domain *d)
struct p2m_domain *p2m = p2m_get_hostp2m(d);

if ( p2m->disable_hardware_log_dirty )
- {
- p2m_lock(p2m);
p2m->disable_hardware_log_dirty(p2m);
- p2m_unlock(p2m);
- }
}

void p2m_flush_hardware_cached_dirty(struct domain *d)
--
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