| Message ID | 20201103160855.261881-1-david.edmondson@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [kvm-unit-tests] x86: check that clflushopt of an MMIO address succeeds | expand |
> 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?
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.
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
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