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author | Jiri Kosina <jkosina@suse.cz> | 2023-11-01 02:07:35 +0300 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2023-11-01 02:07:35 +0300 |
commit | 20cd569d7ee8fce24e8753f0f43af6c420557b1f (patch) | |
tree | f559cfda594846795aa51c99d96f92d8c912851a /tools/testing/selftests/kvm/lib/x86_64/ucall.c | |
parent | 62cc9c3cb3ec1bf31cc116146185ed97b450836a (diff) | |
parent | eeebfe6259ba2d5b0980eb7b0df384eb77e9e4f5 (diff) | |
download | linux-20cd569d7ee8fce24e8753f0f43af6c420557b1f.tar.xz |
Merge branch 'for-6.7/config_pm' into for-linus
- #ifdef CONFIG_PM removal from HID code (Thomas Weißschuh)
Diffstat (limited to 'tools/testing/selftests/kvm/lib/x86_64/ucall.c')
-rw-r--r-- | tools/testing/selftests/kvm/lib/x86_64/ucall.c | 36 |
1 files changed, 30 insertions, 6 deletions
diff --git a/tools/testing/selftests/kvm/lib/x86_64/ucall.c b/tools/testing/selftests/kvm/lib/x86_64/ucall.c index 4d41dc63cc9e..1265cecc7dd1 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/ucall.c +++ b/tools/testing/selftests/kvm/lib/x86_64/ucall.c @@ -8,14 +8,38 @@ #define UCALL_PIO_PORT ((uint16_t)0x1000) -void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa) -{ -} - void ucall_arch_do_ucall(vm_vaddr_t uc) { - asm volatile("in %[port], %%al" - : : [port] "d" (UCALL_PIO_PORT), "D" (uc) : "rax", "memory"); + /* + * FIXME: Revert this hack (the entire commit that added it) once nVMX + * preserves L2 GPRs across a nested VM-Exit. If a ucall from L2, e.g. + * to do a GUEST_SYNC(), lands the vCPU in L1, any and all GPRs can be + * clobbered by L1. Save and restore non-volatile GPRs (clobbering RBP + * in particular is problematic) along with RDX and RDI (which are + * inputs), and clobber volatile GPRs. *sigh* + */ +#define HORRIFIC_L2_UCALL_CLOBBER_HACK \ + "rcx", "rsi", "r8", "r9", "r10", "r11" + + asm volatile("push %%rbp\n\t" + "push %%r15\n\t" + "push %%r14\n\t" + "push %%r13\n\t" + "push %%r12\n\t" + "push %%rbx\n\t" + "push %%rdx\n\t" + "push %%rdi\n\t" + "in %[port], %%al\n\t" + "pop %%rdi\n\t" + "pop %%rdx\n\t" + "pop %%rbx\n\t" + "pop %%r12\n\t" + "pop %%r13\n\t" + "pop %%r14\n\t" + "pop %%r15\n\t" + "pop %%rbp\n\t" + : : [port] "d" (UCALL_PIO_PORT), "D" (uc) : "rax", "memory", + HORRIFIC_L2_UCALL_CLOBBER_HACK); } void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu) |