On 2022-02-22 13:58, Alexandru Elisei wrote:
Hi,
On Tue, Feb 22, 2022 at 10:08:30AM +0000, Sebastian Ene wrote:
This patch adds support for stolen time by sharing a memory region
with the guest which will be used by the hypervisor to store the
stolen
time information. The exact format of the structure stored by the
hypervisor is described in the ARM DEN0057A document.
Signed-off-by: Sebastian Ene <sebastianene@xxxxxxxxxx>
---
Changelog since v2:
- Moved the AARCH64_PVTIME_* definitions from arm-common/kvm-arch.h
to
arm64/pvtime.c as pvtime is only available for arm64.
Changelog since v1:
- Removed the pvtime.h header file and moved the definitions to
kvm-cpu-arch.h
Verified if the stolen time capability is supported before
allocating
and mapping the memory.
Makefile | 1 +
arm/aarch64/arm-cpu.c | 1 +
arm/aarch64/include/kvm/kvm-cpu-arch.h | 1 +
arm/aarch64/pvtime.c | 89
++++++++++++++++++++++++++
arm/kvm-cpu.c | 14 ++--
5 files changed, 99 insertions(+), 7 deletions(-)
create mode 100644 arm/aarch64/pvtime.c
diff --git a/Makefile b/Makefile
index f251147..e9121dc 100644
--- a/Makefile
+++ b/Makefile
@@ -182,6 +182,7 @@ ifeq ($(ARCH), arm64)
OBJS += arm/aarch64/arm-cpu.o
OBJS += arm/aarch64/kvm-cpu.o
OBJS += arm/aarch64/kvm.o
+ OBJS += arm/aarch64/pvtime.o
ARCH_INCLUDE := $(HDRS_ARM_COMMON)
ARCH_INCLUDE += -Iarm/aarch64/include
diff --git a/arm/aarch64/arm-cpu.c b/arm/aarch64/arm-cpu.c
index d7572b7..326fb20 100644
--- a/arm/aarch64/arm-cpu.c
+++ b/arm/aarch64/arm-cpu.c
@@ -22,6 +22,7 @@ static void generate_fdt_nodes(void *fdt, struct kvm
*kvm)
static int arm_cpu__vcpu_init(struct kvm_cpu *vcpu)
{
vcpu->generate_fdt_nodes = generate_fdt_nodes;
+ kvm_cpu__setup_pvtime(vcpu);
return 0;
}
diff --git a/arm/aarch64/include/kvm/kvm-cpu-arch.h
b/arm/aarch64/include/kvm/kvm-cpu-arch.h
index 8dfb82e..b57d6e6 100644
--- a/arm/aarch64/include/kvm/kvm-cpu-arch.h
+++ b/arm/aarch64/include/kvm/kvm-cpu-arch.h
@@ -19,5 +19,6 @@
void kvm_cpu__select_features(struct kvm *kvm, struct kvm_vcpu_init
*init);
int kvm_cpu__configure_features(struct kvm_cpu *vcpu);
+void kvm_cpu__setup_pvtime(struct kvm_cpu *vcpu);
#endif /* KVM__KVM_CPU_ARCH_H */
diff --git a/arm/aarch64/pvtime.c b/arm/aarch64/pvtime.c
new file mode 100644
index 0000000..247e4f3
--- /dev/null
+++ b/arm/aarch64/pvtime.c
@@ -0,0 +1,89 @@
+#include "kvm/kvm.h"
+#include "kvm/kvm-cpu.h"
+#include "kvm/util.h"
+
+#include <linux/byteorder.h>
+#include <linux/types.h>
+
+#define AARCH64_PVTIME_IPA_MAX_SIZE SZ_64K
+#define AARCH64_PVTIME_IPA_START (ARM_MEMORY_AREA - \
+ AARCH64_PVTIME_IPA_MAX_SIZE)
This doesn't change the fact that it overlaps with KVM_PCI_MMIO_AREA,
which is
exposed to the guest in the DTB (see my reply to v2).
Yup, this is a bit of a problem, and overlapping regions are
a big no-no. Why can't the pvtime region be dynamically placed
after the RAM (after checking that there is enough space to
register it in the IPA space)?
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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