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From: Dan Carpenter <dan.carpenter@linaro.org>
To: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Cc: kvm@vger.kernel.org
Subject: [bug report] nVMX: Test Host Segment Registers and Descriptor Tables on vmentry of nested guests
Date: Fri, 2 May 2025 16:06:21 +0300	[thread overview]
Message-ID: <aBTDTdGrZbWDW-Ui@stanley.mountain> (raw)

Hello Krish Sadhukhan,

Commit 95d6d2c32288 ("nVMX: Test Host Segment Registers and
Descriptor Tables on vmentry of nested guests") from Jun 28, 2019
(linux-next), leads to the following Smatch static checker warning:

	x86/vmx_tests.c:7583 test_vmcs_field()
	warn: maybe use && instead of &

x86/vmx_tests.c
    7561 static void test_vmcs_field(u64 field, const char *field_name, u32 bit_start,
    7562                             u32 bit_end, u64 val, bool valid_val, u32 error)
    7563 {
    7564         u64 field_saved = vmcs_read(field);
    7565         u32 i;
    7566         u64 tmp;
    7567         u32 bit_on;
    7568         u64 mask = ~0ull;
    7569 
    7570         mask = (mask >> bit_end) << bit_end;
    7571         mask = mask | ((1 << bit_start) - 1);
    7572         tmp = (field_saved & mask) | (val << bit_start);
    7573 
    7574         vmcs_write(field, tmp);
    7575         report_prefix_pushf("%s %lx", field_name, tmp);
    7576         if (valid_val)
    7577                 test_vmx_vmlaunch(0);
    7578         else
    7579                 test_vmx_vmlaunch(error);
    7580         report_prefix_pop();
    7581 
    7582         for (i = bit_start; i <= bit_end; i = i + 2) {
--> 7583                 bit_on = ((1ull < i) & (val << bit_start)) ? 0 : 1;
                                         ^
This quite looks like it's supposed to be << instead of <.

    7584                 if (bit_on)
    7585                         tmp = field_saved | (1ull << i);
    7586                 else
    7587                         tmp = field_saved & ~(1ull << i);
    7588                 vmcs_write(field, tmp);
    7589                 report_prefix_pushf("%s %lx", field_name, tmp);
    7590                 if (valid_val)
    7591                         test_vmx_vmlaunch(error);
    7592                 else
    7593                         test_vmx_vmlaunch(0);
    7594                 report_prefix_pop();
    7595         }
    7596 
    7597         vmcs_write(field, field_saved);
    7598 }

regards,
dan carpenter

                 reply	other threads:[~2025-05-02 13:06 UTC|newest]

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