From 79033bebf6fa3045bfa9bbe543c0eb7b43a0f4a3 Mon Sep 17 00:00:00 2001 From: Joao Martins Date: Wed, 13 Jun 2018 09:55:44 -0400 Subject: KVM: x86/xen: Fix coexistence of Xen and Hyper-V hypercalls Disambiguate Xen vs. Hyper-V calls by adding 'orl $0x80000000, %eax' at the start of the Hyper-V hypercall page when Xen hypercalls are also enabled. That bit is reserved in the Hyper-V ABI, and those hypercall numbers will never be used by Xen (because it does precisely the same trick). Switch to using kvm_vcpu_write_guest() while we're at it, instead of open-coding it. Signed-off-by: David Woodhouse --- .../testing/selftests/kvm/x86_64/xen_vmcall_test.c | 39 ++++++++++++++++++---- 1 file changed, 33 insertions(+), 6 deletions(-) (limited to 'tools') diff --git a/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c b/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c index 234c9da286aa..6e7b069322fd 100644 --- a/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c +++ b/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c @@ -15,6 +15,7 @@ #define HCALL_REGION_GPA 0xc0000000ULL #define HCALL_REGION_SLOT 10 +#define PAGE_SIZE 4096 static struct kvm_vm *vm; @@ -22,7 +23,12 @@ static struct kvm_vm *vm; #define ARGVALUE(x) (0xdeadbeef5a5a0000UL + x) #define RETVALUE 0xcafef00dfbfbffffUL -#define XEN_HYPERCALL_MSR 0x40000000 +#define XEN_HYPERCALL_MSR 0x40000200 +#define HV_GUEST_OS_ID_MSR 0x40000000 +#define HV_HYPERCALL_MSR 0x40000001 + +#define HVCALL_SIGNAL_EVENT 0x005d +#define HV_STATUS_INVALID_ALIGNMENT 4 static void guest_code(void) { @@ -30,6 +36,7 @@ static void guest_code(void) unsigned long rdi = ARGVALUE(1); unsigned long rsi = ARGVALUE(2); unsigned long rdx = ARGVALUE(3); + unsigned long rcx; register unsigned long r10 __asm__("r10") = ARGVALUE(4); register unsigned long r8 __asm__("r8") = ARGVALUE(5); register unsigned long r9 __asm__("r9") = ARGVALUE(6); @@ -41,18 +48,38 @@ static void guest_code(void) "r"(r10), "r"(r8), "r"(r9)); GUEST_ASSERT(rax == RETVALUE); - /* Now fill in the hypercall page */ + /* Fill in the Xen hypercall page */ __asm__ __volatile__("wrmsr" : : "c" (XEN_HYPERCALL_MSR), "a" (HCALL_REGION_GPA & 0xffffffff), "d" (HCALL_REGION_GPA >> 32)); - /* And invoke the same hypercall that way */ + /* Set Hyper-V Guest OS ID */ + __asm__ __volatile__("wrmsr" : : "c" (HV_GUEST_OS_ID_MSR), + "a" (0x5a), "d" (0)); + + /* Hyper-V hypercall page */ + u64 msrval = HCALL_REGION_GPA + PAGE_SIZE + 1; + __asm__ __volatile__("wrmsr" : : "c" (HV_HYPERCALL_MSR), + "a" (msrval & 0xffffffff), + "d" (msrval >> 32)); + + /* Invoke a Xen hypercall */ __asm__ __volatile__("call *%1" : "=a"(rax) : "r"(HCALL_REGION_GPA + INPUTVALUE * 32), "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx), "r"(r10), "r"(r8), "r"(r9)); GUEST_ASSERT(rax == RETVALUE); + /* Invoke a Hyper-V hypercall */ + rax = 0; + rcx = HVCALL_SIGNAL_EVENT; /* code */ + rdx = 0x5a5a5a5a; /* ingpa (badly aligned) */ + __asm__ __volatile__("call *%1" : "=a"(rax) : + "r"(HCALL_REGION_GPA + PAGE_SIZE), + "a"(rax), "c"(rcx), "d"(rdx), + "r"(r8)); + GUEST_ASSERT(rax == HV_STATUS_INVALID_ALIGNMENT); + GUEST_DONE(); } @@ -73,11 +100,11 @@ int main(int argc, char *argv[]) }; vm_ioctl(vm, KVM_XEN_HVM_CONFIG, &hvmc); - /* Map a region for the hypercall page */ + /* Map a region for the hypercall pages */ vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, HCALL_REGION_GPA, HCALL_REGION_SLOT, - getpagesize(), 0); - virt_map(vm, HCALL_REGION_GPA, HCALL_REGION_GPA, 1, 0); + 2 * getpagesize(), 0); + virt_map(vm, HCALL_REGION_GPA, HCALL_REGION_GPA, 2, 0); for (;;) { volatile struct kvm_run *run = vcpu_state(vm, VCPU_ID); -- cgit