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| author | Sean Christopherson <seanjc@google.com> | 2024-11-27 16:43:39 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-12-27 14:02:15 +0100 |
| commit | 22b5c2acd65dbe949032f619d4758a35a82fffc3 (patch) | |
| tree | c967337dc204bb8be51647939d7a339da84c1d7b /arch | |
| parent | bacd0498dea04be58804f428d9f8695777fde4c9 (diff) | |
| download | linux-22b5c2acd65dbe949032f619d4758a35a82fffc3.tar.gz linux-22b5c2acd65dbe949032f619d4758a35a82fffc3.tar.bz2 linux-22b5c2acd65dbe949032f619d4758a35a82fffc3.zip | |
KVM: x86: Play nice with protected guests in complete_hypercall_exit()
commit 9b42d1e8e4fe9dc631162c04caa69b0d1860b0f0 upstream.
Use is_64_bit_hypercall() instead of is_64_bit_mode() to detect a 64-bit
hypercall when completing said hypercall. For guests with protected state,
e.g. SEV-ES and SEV-SNP, KVM must assume the hypercall was made in 64-bit
mode as the vCPU state needed to detect 64-bit mode is unavailable.
Hacking the sev_smoke_test selftest to generate a KVM_HC_MAP_GPA_RANGE
hypercall via VMGEXIT trips the WARN:
------------[ cut here ]------------
WARNING: CPU: 273 PID: 326626 at arch/x86/kvm/x86.h:180 complete_hypercall_exit+0x44/0xe0 [kvm]
Modules linked in: kvm_amd kvm ... [last unloaded: kvm]
CPU: 273 UID: 0 PID: 326626 Comm: sev_smoke_test Not tainted 6.12.0-smp--392e932fa0f3-feat #470
Hardware name: Google Astoria/astoria, BIOS 0.20240617.0-0 06/17/2024
RIP: 0010:complete_hypercall_exit+0x44/0xe0 [kvm]
Call Trace:
<TASK>
kvm_arch_vcpu_ioctl_run+0x2400/0x2720 [kvm]
kvm_vcpu_ioctl+0x54f/0x630 [kvm]
__se_sys_ioctl+0x6b/0xc0
do_syscall_64+0x83/0x160
entry_SYSCALL_64_after_hwframe+0x76/0x7e
</TASK>
---[ end trace 0000000000000000 ]---
Fixes: b5aead0064f3 ("KVM: x86: Assume a 64-bit hypercall for guests with protected state")
Cc: stable@vger.kernel.org
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Nikunj A Dadhania <nikunj@amd.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20241128004344.4072099-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/x86.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 897200eed0ce..b49e2eb48930 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9991,7 +9991,7 @@ static int complete_hypercall_exit(struct kvm_vcpu *vcpu) { u64 ret = vcpu->run->hypercall.ret; - if (!is_64_bit_mode(vcpu)) + if (!is_64_bit_hypercall(vcpu)) ret = (u32)ret; kvm_rax_write(vcpu, ret); ++vcpu->stat.hypercalls; |