mirror of
https://github.com/torvalds/linux.git
synced 2026-05-26 08:02:27 +02:00
19d0914920
Use u16 instead of uint16_t to make the KVM selftests code more concise and more similar to the kernel (since selftests are primarily developed by kernel developers). This commit was generated with the following command: git ls-files tools/testing/selftests/kvm | xargs sed -i 's/uint16_t/u16/g' Then by manually adjusting whitespace to make checkpatch.pl happy. No functional change intended. Signed-off-by: David Matlack <dmatlack@google.com> Link: https://patch.msgid.link/20260420212004.3938325-9-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
57 lines
1.5 KiB
C
57 lines
1.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* ucall support. A ucall is a "hypercall to userspace".
|
|
*
|
|
* Copyright (C) 2018, Red Hat, Inc.
|
|
*/
|
|
#include "kvm_util.h"
|
|
|
|
#define UCALL_PIO_PORT ((u16)0x1000)
|
|
|
|
void ucall_arch_do_ucall(gva_t uc)
|
|
{
|
|
/*
|
|
* 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)
|
|
{
|
|
struct kvm_run *run = vcpu->run;
|
|
|
|
if (run->exit_reason == KVM_EXIT_IO && run->io.port == UCALL_PIO_PORT) {
|
|
struct kvm_regs regs;
|
|
|
|
vcpu_regs_get(vcpu, ®s);
|
|
return (void *)regs.rdi;
|
|
}
|
|
return NULL;
|
|
}
|