From: Tom Lendacky <thomas.lendacky@xxxxxxx>
In preparation for an upcoming patch, convert the mutex that guards the
DEACTIVATE/WBINVD/DF_FLUSH sequence into a read/write semaphore. The
conversion will convert the mutex lock and unlock into down_write and
up_write so that the mutex behavior is maintained.
Tested-by: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
---
arch/x86/kvm/svm.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 389dfd7594eb..b995d7ac1516 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -38,6 +38,7 @@
#include <linux/file.h>
#include <linux/pagemap.h>
#include <linux/swap.h>
+#include <linux/rwsem.h>
#include <asm/apic.h>
#include <asm/perf_event.h>
@@ -418,7 +419,7 @@ enum {
#define VMCB_AVIC_APIC_BAR_MASK 0xFFFFFFFFFF000ULL
-static DEFINE_MUTEX(sev_deactivate_lock);
+static DECLARE_RWSEM(sev_deactivate_lock);
static DEFINE_MUTEX(sev_bitmap_lock);
static unsigned int max_sev_asid;
static unsigned int min_sev_asid;
@@ -1762,14 +1763,14 @@ static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
* Guard against a parallel DEACTIVATE command before the DF_FLUSH
* command has completed.
*/
- mutex_lock(&sev_deactivate_lock);
+ down_write(&sev_deactivate_lock);
sev_guest_deactivate(data, NULL);
wbinvd_on_all_cpus();
sev_guest_df_flush(NULL);
- mutex_unlock(&sev_deactivate_lock);
+ up_write(&sev_deactivate_lock);
kfree(data);
--
2.17.1
