* [kvm-unit-tests PATCH] x86: check that clflushopt of an MMIO address succeeds
@ 2020-11-03 16:08 David Edmondson
2020-11-05 7:53 ` Nadav Amit
0 siblings, 1 reply; 3+ messages in thread
From: David Edmondson @ 2020-11-03 16:08 UTC (permalink / raw)
To: kvm; +Cc: David Edmondson, Joao Martins
Verify that the clflushopt instruction succeeds when applied to an
MMIO address at both cpl0 and cpl3.
Suggested-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: David Edmondson <david.edmondson@oracle.com>
---
This is a test for the fix included in:
https://lore.kernel.org/r/20201103120400.240882-1-david.edmondson@oracle.com
x86/Makefile.common | 3 ++-
x86/clflushopt_mmio.c | 58 +++++++++++++++++++++++++++++++++++++++++++
x86/unittests.cfg | 5 ++++
3 files changed, 65 insertions(+), 1 deletion(-)
create mode 100644 x86/clflushopt_mmio.c
diff --git a/x86/Makefile.common b/x86/Makefile.common
index b942086..e11666a 100644
--- a/x86/Makefile.common
+++ b/x86/Makefile.common
@@ -62,7 +62,8 @@ tests-common = $(TEST_DIR)/vmexit.flat $(TEST_DIR)/tsc.flat \
$(TEST_DIR)/init.flat $(TEST_DIR)/smap.flat \
$(TEST_DIR)/hyperv_synic.flat $(TEST_DIR)/hyperv_stimer.flat \
$(TEST_DIR)/hyperv_connections.flat \
- $(TEST_DIR)/umip.flat $(TEST_DIR)/tsx-ctrl.flat
+ $(TEST_DIR)/umip.flat $(TEST_DIR)/tsx-ctrl.flat \
+ $(TEST_DIR)/clflushopt_mmio.flat
test_cases: $(tests-common) $(tests)
diff --git a/x86/clflushopt_mmio.c b/x86/clflushopt_mmio.c
new file mode 100644
index 0000000..06c1b32
--- /dev/null
+++ b/x86/clflushopt_mmio.c
@@ -0,0 +1,58 @@
+#include "libcflat.h"
+#include "usermode.h"
+#include "pci.h"
+#include "x86/asm/pci.h"
+
+static volatile int ud;
+static void *memaddr;
+
+static void handle_ud(struct ex_regs *regs)
+{
+ ud = 1;
+ regs->rip += 4;
+}
+
+static void try_clflushopt(const char *comment)
+{
+ int expected = !this_cpu_has(X86_FEATURE_CLFLUSHOPT);
+
+ ud = 0;
+ /* clflushopt (%rbx): */
+ asm volatile(".byte 0x66, 0x0f, 0xae, 0x3b" : : "b" (memaddr));
+
+ report(ud == expected, comment, expected ? "ABSENT" : "present");
+}
+
+static uint64_t user_clflushopt(void)
+{
+ try_clflushopt("clflushopt-mmio@cpl3 (%s)");
+
+ return 0;
+}
+
+int main(int ac, char **av)
+{
+ int ret;
+ struct pci_dev pcidev;
+ unsigned long membar = 0;
+ bool raised;
+
+ setup_vm();
+
+ ret = pci_find_dev(PCI_VENDOR_ID_REDHAT, PCI_DEVICE_ID_REDHAT_TEST);
+ if (ret != PCIDEVADDR_INVALID) {
+ pci_dev_init(&pcidev, ret);
+ assert(pci_bar_is_memory(&pcidev, PCI_TESTDEV_BAR_MEM));
+ membar = pcidev.resource[PCI_TESTDEV_BAR_MEM];
+ memaddr = ioremap(membar, PAGE_SIZE);
+ printf("pci-testdev at %#x membar %lx (@%p)\n",
+ pcidev.bdf, membar, memaddr);
+
+ handle_exception(UD_VECTOR, handle_ud);
+
+ (void) run_in_user(user_clflushopt, false, 0, 0, 0, 0, &raised);
+ try_clflushopt("clflushopt-mmio@cpl0 (%s)");
+ }
+
+ return report_summary();
+}
diff --git a/x86/unittests.cfg b/x86/unittests.cfg
index 872d679..35bedf8 100644
--- a/x86/unittests.cfg
+++ b/x86/unittests.cfg
@@ -359,3 +359,8 @@ extra_params = -M q35,kernel-irqchip=split -device intel-iommu,intremap=on,eim=o
file = tsx-ctrl.flat
extra_params = -cpu host
groups = tsx-ctrl
+
+[clflushopt_mmio]
+file = clflushopt_mmio.flat
+extra_params = -cpu host
+arch = x86_64
--
2.28.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [kvm-unit-tests PATCH] x86: check that clflushopt of an MMIO address succeeds
2020-11-03 16:08 [kvm-unit-tests PATCH] x86: check that clflushopt of an MMIO address succeeds David Edmondson
@ 2020-11-05 7:53 ` Nadav Amit
2020-11-05 10:20 ` David Edmondson
0 siblings, 1 reply; 3+ messages in thread
From: Nadav Amit @ 2020-11-05 7:53 UTC (permalink / raw)
To: David Edmondson; +Cc: KVM, Joao Martins
> On Nov 3, 2020, at 8:08 AM, David Edmondson <david.edmondson@oracle.com> wrote:
>
> Verify that the clflushopt instruction succeeds when applied to an
> MMIO address at both cpl0 and cpl3.
>
> Suggested-by: Joao Martins <joao.m.martins@oracle.com>
> Signed-off-by: David Edmondson <david.edmondson@oracle.com>
>
[snip]
> + ret = pci_find_dev(PCI_VENDOR_ID_REDHAT, PCI_DEVICE_ID_REDHAT_TEST);
> + if (ret != PCIDEVADDR_INVALID) {
> + pci_dev_init(&pcidev, ret);
Just wondering, and perhaps this question is more general: does this test
really need the Red-Hat test device?
I know it is an emulated device, but can’t we use some other MMIO address
(e.g., PIT) that is also available on bare-metal?
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [kvm-unit-tests PATCH] x86: check that clflushopt of an MMIO address succeeds
2020-11-05 7:53 ` Nadav Amit
@ 2020-11-05 10:20 ` David Edmondson
0 siblings, 0 replies; 3+ messages in thread
From: David Edmondson @ 2020-11-05 10:20 UTC (permalink / raw)
To: Nadav Amit; +Cc: KVM, Joao Martins
On Wednesday, 2020-11-04 at 23:53:01 -08, Nadav Amit wrote:
>> On Nov 3, 2020, at 8:08 AM, David Edmondson <david.edmondson@oracle.com> wrote:
>>
>> Verify that the clflushopt instruction succeeds when applied to an
>> MMIO address at both cpl0 and cpl3.
>>
>> Suggested-by: Joao Martins <joao.m.martins@oracle.com>
>> Signed-off-by: David Edmondson <david.edmondson@oracle.com>
>>
>
> [snip]
>
>> + ret = pci_find_dev(PCI_VENDOR_ID_REDHAT, PCI_DEVICE_ID_REDHAT_TEST);
>> + if (ret != PCIDEVADDR_INVALID) {
>> + pci_dev_init(&pcidev, ret);
>
> Just wondering, and perhaps this question is more general: does this test
> really need the Red-Hat test device?
>
> I know it is an emulated device, but can’t we use some other MMIO address
> (e.g., PIT) that is also available on bare-metal?
If it's acceptable to assume that HPET is present and at 0xfed00000,
then it could be used.
dme.
--
Does everyone stare the way I do?
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2020-11-05 10:20 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-11-03 16:08 [kvm-unit-tests PATCH] x86: check that clflushopt of an MMIO address succeeds David Edmondson
2020-11-05 7:53 ` Nadav Amit
2020-11-05 10:20 ` David Edmondson
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).